Light guide protection structures for plasma system to disrupt vascular lesions

ABSTRACT

A catheter system includes a catheter having an elongate shaft, a balloon and a light guide. The balloon expands from a collapsed configuration to a first expanded configuration. The light guide is disposed along the elongate shaft and is in optical communication with a light source and a balloon fluid. A first portion of the light guide extends into a recess defined by the elongate shaft. A protection structure is disposed within the recess and is in contact with the first portion of the light guide. The light source provides pulses of light to the balloon fluid, thereby initiating plasma formation and rapid bubble formation within the balloon, thereby imparting pressure waves upon a vascular lesion. The protection structure can provide structural protection from the pressure waves to the first portion of the light guide.

RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 16/904,282, filed on Jun. 17, 2020, entitled “LIGHTGUIDE PROTECTION STRUCTURES FOR PLASMA SYSTEM TO DISRUPT VASCULARLESIONS.” Additionally, U.S. patent application Ser. No. 16/904,282claims priority on U.S. Provisional Application Ser. No. 62/866,981,filed on Jun. 26, 2019, and entitled “SIDE LIGHT DIRECTION PLASMA SYSTEMTO DISRUPT VASCULAR LESIONS,” on U.S. Provisional Application No.62/867,009, filed on Jun. 26, 2019, entitled, “LIGHT GUIDE PROTECTIONSTRUCTURES FOR PLASMA SYSTEM TO DISRUPT VASCULAR LESIONS,” on U.S.Provisional Application No. 62/867,026, filed on Jun. 26, 2019,entitled, “FORTIFIED BALLOON INFLATION FLUID FOR PLASMA SYSTEM TODISRUPT VASCULAR LESIONS,” and on U.S. Provisional Application No.62/867,034, filed on Jun. 26, 2019, entitled, “FOCUSING ELEMENT FORPLASMA SYSTEM TO DISRUPT VASCULAR LESIONS,” the contents of which foreach application are herein incorporated by reference in their entiretyto the extent permitted.

BACKGROUND

Vascular lesions within vessels in the body can be associated with anincreased risk for major adverse events, such as myocardial infarction,embolism, deep vein thrombosis, stroke, and the like. Severe vascularlesions can be difficult to treat and achieve patency for a physician ina clinical setting.

Vascular lesions may be treated using interventions such as drugtherapy, balloon angioplasty, atherectomy, stent placement, vasculargraft bypass, to name a few. Such interventions may not always be idealor may require subsequent treatment to address the lesion.

SUMMARY

In a first aspect, a catheter system for imparting pressure to inducefractures in a vascular lesion within or adjacent a vessel wall includesa catheter and a first protection structure. The catheter includes anelongate shaft, a balloon and a first light guide. The balloon iscoupled to the elongate shaft. The first light guide is disposed alongthe elongate shaft. The elongate shaft defines a first recess within theballoon. The balloon is configured to be filled with a balloon fluid.The first light guide is positioned at least partially within theballoon and is in optical communication with a light source and theballoon fluid. The first light guide includes a first portion thatextends into the first recess. The first protection structure contactsthe first portion of the first light guide. The light source selectivelyprovides pulses of light through the first light guide to the balloonfluid so that plasma formation and rapid bubble formation in the balloonfluid occur, thereby imparting pressure waves upon the vascular lesion.The first protection structure is configured to provide structuralprotection from the pressure waves to the first portion of the firstlight guide.

In a second aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the firstportion includes a distal tip of the first light guide, and the firstprotection structure is configured to provide structural protection tothe distal tip of the first light guide.

In a third aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the firstprotection structure includes an end cap disposed about a distal portionof the first portion of the light guide and can be adhered to an outersurface of the distal portion of the first portion of the light guidewith an adhesive, where the adhesive and the end cap are opticallymatched to the first light guide.

In a fourth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the firstprotection structure includes a potting material at least partiallyfilling the first recess, where the potting material is opticallymatched to the first light guide.

In a fifth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the firstprotection structure includes a first component abutted against andfused to the distal tip of the first light guide, where the firstcomponent is optically matched to the first light guide.

In a sixth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the lightguide further includes a diverting feature selected from a group caninclude at least one of a reflecting element, a refracting element, or afiber diffuser.

In a seventh aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the divertingfeature includes a fiber diffuser selected from a group including of amachined portion of the light guide, a laser-machined portion of thelight guide, fiber Bragg gratings, a fused splicing forming at least oneinternal mirror, and a splicing of two or more diffuse regions.

In an eighth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, the divertingfeature includes a fused splicing forming at least one internal mirrorand the first light guide further includes a first light window inoptical communication with the diverting feature.

In a ninth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst light guide is an optical fiber and the light source is a laser.

In a tenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where theelongate shaft defines an inflation lumen, and where the inflation lumenis in fluid communication with the balloon at a distal portion of theelongate shaft.

In an eleventh aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst recess is a longitudinal recess along a longitudinal surface ofthe elongate shaft.

In a twelfth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where theelongate shaft further defines a second recess within the balloon alonga longitudinal surface of the elongate shaft; where a second portion ofthe first light guide extends into the second recess and the secondportion defines a longitudinal light window disposed along alongitudinal length of the second portion and in optical communicationwith a first diverting feature; and where the catheter further includesa first longitudinal protection structure in contact with the secondportion of the first light guide and configured to provide structuralprotection to the second portion in the presence of the pressure waves.

In a thirteenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst longitudinal protection structure includes a potting material atleast partially disposed within the second recess, and where the pottingmaterial is optically matched to the first light guide.

In a fourteenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst longitudinal protection structure includes a sleeve disposed aboutthe longitudinal light window and adhered to the longitudinal surface ofthe second portion of the first light guide with an adhesive, and wherethe adhesive and the sleeve are optically matched to the first lightguide.

In a fifteenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst longitudinal protection structure includes a first component fusedbetween a proximal tip of the second portion of the first light guideand a distal tip of a second light guide; where the second light guideextends in a distal direction into the second recess and includes adistal tip in the second recess; where the first light guide extends ina proximal direction into the second recess and includes a proximal tip;where the first component is abutted against and fused to the distal tipof the second light guide and the proximal tip of the second portion;and where the first component is optically matched to the first andsecond light guides.

In a sixteenth aspect, a catheter system for imparting pressure toinduce fractures in a vascular lesion within or adjacent a blood vesselwall is included. The catheter systems can include a catheter configuredto advance to the vascular lesion located within or adjacent a bloodvessel, where the catheter can include an elongate shaft and a ballooncoupled to the elongate shaft. The balloon can be configured to befilled with balloon fluid and configured to expand from a collapsedconfiguration suitable for advancing the catheter through a patient'svasculature to a first expanded configuration suitable for anchoring thecatheter in position relative to a treatment site. The elongate shaftcan define a first recess within the balloon. The catheter can include afirst light guide disposed along the elongate shaft and within theballoon, where the first light guide can be configured to be placed inoptical communication with a light source and a balloon fluid. Thecatheter can include a first portion of the first light guide thatextends into the first recess and includes a distal tip of the firstlight guide. The catheter can include a first protection structuredisposed within the first recess of the elongate shaft and in contactwith the first portion of the light guide. The first protectionstructure can include a potting material filling the first recess. Thelight source can be configured to provide pulses of light to the balloonfluid, thereby initiating plasma formation in the balloon fluid, causingrapid bubble formation, and imparting pressure waves upon the vascularlesion. The first protection structure can be configured to providestructural protection to the first portion and distal tip of the firstlight guide in the presence of the pressure waves.

In a seventeenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thepotting material at least partially fills the first recess and includesa potting material outer surface; and where the potting material isoptically matched to the first light guide.

In an eighteenth aspect, a method for generating pressure waves toinduce fractures in a vascular lesion within or adjacent a vessel wallincludes the steps of: advancing a catheter to the vascular lesion, thecatheter comprising an elongate shaft, a balloon coupled to the elongateshaft, and a first light guide disposed along the elongate shaft andpositioned at least partially within the balloon, the first light guidebeing configured to be in optical communication with a light source anda balloon fluid, a first portion of the first light guide being disposedwithin a first recess that is defined by the elongate shaft, wherein thefirst portion of the first light guide is in contact with a first lightguide protection structure of the catheter; expanding the balloon to afirst expanded configuration; and activating a light source in opticalcommunication with the first light guide to direct light from within thefirst light guide to initiate plasma formation and rapid bubbleformation in the balloon, thereby imparting pressure waves upon thevascular lesion, wherein the first light guide protection structure isconfigured to provide structural protection from the pressure waves tothe first portion of the first light guide.

In a nineteenth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, where thefirst portion includes a distal tip of the first light guide, and wherethe first protection structure is configured to provide structuralprotection to the distal tip of the first light guide.

In a twentieth aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, further caninclude, after activating the light source, further expanding theballoon from the first expanded configuration to a second furtherexpanded configuration.

In a twenty-first aspect, in addition to one or more of the preceding orfollowing aspects, or in the alternative to some aspects, a cathetersystem for imparting pressure to induce fractures in a vascular lesionwithin or adjacent a vessel wall includes a catheter and a firstprotection structure. The catheter includes an elongate shaft, a balloonand an optical fiber. The balloon is coupled to the elongate shaft. Theoptical fiber is disposed along the elongate shaft. The elongate shaftdefines a first recess within the balloon. The balloon is configured tobe filled with a balloon fluid. The optical fiber is positioned at leastpartially within the balloon and is in optical communication with alaser and the balloon fluid. The optical fiber includes a first portionthat extends into the first recess, the first portion including a distaltip of the optical fiber. The first protection structure contacts thefirst portion of the optical fiber. The first protection structure caninclude a potting material that at least partially fills the firstrecess, the potting material being optically matched to the opticalfiber. The laser selectively provides pulses of light through theoptical fiber to the balloon fluid so that plasma formation and rapidbubble formation in the balloon fluid occur, thereby imparting pressurewaves upon the vascular lesion. The first protection structure isconfigured to provide structural protection from the pressure waves tothe distal tip of the first portion of the optical fiber.

This summary is an overview of some of the teachings of the presentapplication and is not intended to be an exclusive or exhaustivetreatment of the present subject matter. Further details are found inthe detailed description and appended claims. Other aspects will beapparent to persons skilled in the art upon reading and understandingthe following detailed description and viewing the drawings that form apart thereof, each of which is not to be taken in a limiting sense. Thescope herein is defined by the appended claims and their legalequivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a schematic cross-sectional view of a catheter in accordancewith various embodiments herein.

FIG. 2 is a schematic cross-sectional view of an elongate shaft andmultiple light guides of a catheter along line 2-2′ in FIG. 1 inaccordance with various embodiments herein.

FIGS. 3-5 are schematic cross-sectional views of additionalconfigurations for an elongate shaft and multiple light guides of acatheter along line 2-2′ in FIG. 1 in accordance with variousembodiments herein.

FIG. 6 is a schematic cross-sectional view of a light guide inaccordance with various embodiments herein.

FIG. 7 is a schematic cross-sectional view of a light guide inaccordance with various embodiments herein.

FIG. 8 is a schematic cross-sectional view of a light guide inaccordance with various embodiments herein.

FIG. 9 is a schematic cross-sectional view of a light guide inaccordance with various embodiments herein.

FIG. 10 is a schematic flow diagram for a method in accordance with thevarious embodiments herein.

FIG. 11 is a schematic side-view of a catheter, with a partiallongitudinal cross-sectional view of a balloon, in accordance withvarious embodiments herein.

FIGS. 12-13 are schematic side views of an elongate shaft in accordancewith various embodiments herein.

FIGS. 14-15 are schematic cross-sectional views of various distal tipprotection structures in accordance with various embodiments herein.

FIGS. 16-18 are schematic cross-sectional views of various longitudinalprotection structures in accordance with various embodiments herein.

FIG. 19 is a schematic side-view of a catheter, with a partiallongitudinal cross-sectional view of a balloon, in accordance withvarious embodiments herein.

FIGS. 20-21 are schematic cross-sectional views of various light guideshaving multiple focusing elements in accordance with various embodimentsherein.

FIGS. 22-23 are cross-sectional views of various catheters including afortification component coating on a surface within a balloon.

FIGS. 24-29 are schematic cross-sectional views of various embodimentsof a distal portion of a light guide of a catheter in accordance withvarious embodiments herein.

FIG. 30-41 are schematic cross-sectional views of additional embodimentsof an elongate shaft of a catheter in accordance with variousembodiments herein

While embodiments are susceptible to various modifications andalternative forms, specifics thereof have been shown by way of exampleand drawings, and will be described in detail. It should be understood,however, that the scope herein is not limited to the particular aspectsdescribed. On the contrary, the intention is to cover modifications,equivalents, and alternatives falling within the spirit and scopeherein.

DESCRIPTION

Treatment of vascular lesions can reduce major adverse events or deathin affected subjects. A major adverse event is one that can occuranywhere within the body due to the presence of a vascular lesion. Majoradverse events can include, but are not limited to major adverse cardiacevents, major adverse events in the peripheral or central vasculature,major adverse events in the brain, major adverse events in themusculature, or major adverse events in any of the internal organs.

The systems and methods disclosed herein describe the use of a cathetersystems including any number of light guides for generating pressurewaves within a balloon for disrupting intervascular lesions. Thecatheter systems herein utilize light energy to generate a plasma at ornear a light guide disposed in a balloon located at a treatment site,where the treatment site can include a vascular lesion such as acalcified vascular lesion or a fibrous vascular lesion. The plasmaformation can initiate a shockwave and can initiate the rapid formationof one or more bubbles that can rapidly expand to a maximum size andthen dissipate through a cavitation event that can launch a shockwaveupon collapse. The rapid expansion of the plasma-induced bubbles cangenerate one or more pressure waves within a balloon fluid and therebyimpart pressure waves upon the treatment site. The pressure waves cantransfer mechanical energy through an incompressible balloon fluid to atreatment site to impart a facture force on an intravascular lesion.Without wishing to be bound by any particular theory, it is believedthat the rapid change in balloon fluid momentum upon a balloon wall thatis in contact with an intravascular lesion is transferred to theintravascular lesion to induce fractures to the lesion.

The catheter systems herein are configured to impart pressure to inducefractures in a vascular lesion within or adjacent a blood vessel wall.The catheter systems can include a catheter configured to advance to thevascular lesion located within or adjacent a blood vessel, where thecatheters include an elongate shaft. The catheters also include one ormore light guides disposed along the elongate shaft and within aballoon. Each light guide can be configured to be placed in opticalcommunication with a light source.

Light Directed Toward a Balloon Wall (FIG. 1)

The light guides herein can be configured to include one or morediverting features configured to direct light to exit from the lightguide toward a side surface portion of the light guide and toward theballoon wall. The diverting features direct light to exit in a directionaway from the axis of the light guide, or in an off-axis direction. Thelight guides can each include one or more light windows disposed alongthe longitudinal or axial surfaces of each light guide and in opticalcommunication with a diverting feature. The light windows can include aportion of the light guide that allows light to exit the light guidefrom within the light guide, such as a portion of the light guidelacking a cladding material on or about the light guide. The balloonsherein can be coupled to the elongate shaft and can be inflated with aballoon fluid.

The balloons herein can include a balloon wall and can be configured toexpand from a collapsed configuration suitable for advancing thecatheter through a patient's vasculature to a first expandedconfiguration suitable for anchoring the catheter in position relativeto a treatment site. The light source can be configured to providesub-millisecond pulses of a light from the light source to one or morelight windows, and thereby initiate plasma formation in a balloon fluidat or near the light windows to cause rapid bubble formation and toimpart pressure waves upon the treatment site.

As used herein, the terms “intravascular lesion” and “vascular lesion”are used interchangeably unless otherwise noted.

It will be appreciated that the catheter systems herein can include manydifferent forms. Referring now to FIG. 1 , a schematic cross-sectionalview is shown of a catheter in accordance with various embodimentsherein. Catheter system 100 is suitable for imparting pressure to inducefractures in a vascular lesion within or adjacent a vessel wall of ablood vessel. Catheter system 100 includes a catheter 101. Catheter 101can be configured to advance to a treatment site within or adjacent ablood vessel. In some embodiments, the treatment site includes avascular lesion such as a calcified vascular lesion. In otherembodiments, the treatment site includes a vascular lesion such as afibrous vascular lesion.

The catheter 101 can include an elongate shaft 102 and a balloon 122coupled to the elongate shaft 102. The elongate shaft 102 can extendfrom a proximal portion 104 to a distal portion 106, and can alsoinclude a lumen 108. The catheter 101 can include a guidewire 126. Insome embodiments, the catheter 101 includes a guidewire lumen. Theelongate shaft 102 can further include an inflation lumen. Various lumenconfigurations and their uses will be discussed in more detail below. Insome embodiments, the catheter 101 can have a distal end opening and canaccommodate and be tracked over guidewire 126 to a treatment site. Insome embodiments, the catheter 101 does not include a guidewire lumen.In embodiments where the elongate shaft 102 does not include a lumen tobe accessed by a caregiver, the elongate shaft 102 can be configured toallow the catheter to be steered through a patient's vasculature.

The elongate shaft 102 of catheter 101 can be coupled to a first lightguide 110 and a second light guide (not shown) in optical communicationwith a light source 116. The first light guide and second light guidecan be disposed along the elongate shaft and within the balloon. It willbe appreciated that the second light guide of catheter 101 can be offsetfrom first light guide 110 by 180 degrees about the elongate shaft 102such that it is obstructed by first light guide 110 in FIG. 1 . In someembodiments, the first light guide 110 and second light guide can beoptical fibers and the light source can be a laser. The light source 116can be in optical communication with the first light guide 110 andsecond light guide at a proximal portion 104 of the elongate shaft 102.In some embodiments, the elongate shaft can be coupled to multiple lightguides such as a third light guide and a fourth light guide. The lightsource 116 can be in optical communication with the third light guideand the fourth light guide at a proximal portion 104 of the elongateshaft 102. In some embodiments, the elongate shaft can be coupled tomore than a fourth light guide.

The balloon 122 of catheter 101 can include a balloon wall and canexpand from a collapsed configuration suitable for advancing thecatheter through a patient's vasculature to a first expandedconfiguration suitable for anchoring the catheter in position relativeto a treatment site. Expansion of the balloons herein to variousexpanded configurations will be discussed in more detail below. Thelight source 116 of catheter system 100 can be configured to providesub-millisecond pulses of light from the light source through the atleast first light window and second light window, thereby inducingplasma formation in a balloon fluid, causing rapid bubble formation, andimparting pressure waves upon the treatment site. Exemplaryplasma-induced bubbles are shown as bubbles 130 in FIG. 1 . In someembodiments, the balloon fluid can be a liquid. Suitable balloon fluidsfor use herein will be discussed in more detail below. In an embodiment,a catheter herein can include a single light guide. The single lightguide can include one or more light windows to direct light out the sideof the light guide and toward a balloon wall. In one embodiment, thesingle light guide can include two light windows that can direct lighttoward a balloon wall in unison.

The sub-millisecond pulses of light can be delivered to a treatment siteat a frequency of from at least 1 hertz (Hz) to 5000 Hz. In someembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency from at least 30 Hz to 1000 Hz. In otherembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency from at least 10 Hz to 100 Hz. In yetother embodiments, the sub-millisecond pulses of light can be deliveredto a treatment site at a frequency from at least 1 Hz to 30 Hz. In someembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency that can be greater than or equal to 1 Hz,2 Hz, 3 Hz, 4 Hz, 5 Hz, 6 Hz, 7 Hz, 8 Hz, or 9 Hz, 10 Hz, 20 Hz, 30 Hz,40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, 100 Hz, 200 Hz, 300 Hz, 400Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz, 900 Hz, 1000 Hz, 1250 Hz, 1500 Hz,1750 Hz, 2000 Hz, 2250 Hz, 2500 Hz, 2750 Hz, 3000 Hz, 3250 Hz, 3500 Hz,3750 Hz, 4000 Hz, 4250 Hz, 4500 Hz, 4750 Hz, or 5000 Hz or can be anamount falling within a range between any of the foregoing.

It will be appreciated that the catheters herein can include any numberof light guides in optical communication with the light source 116 atthe proximal portion 104 and a balloon fluid 124 within balloon 122 atthe distal portion 106. For example, in some embodiments, the cathetersherein can include from one light guide to five light guides. In otherembodiments, the catheters herein can include from five light guides tofifteen light guides. In yet other embodiments, the catheters herein caninclude from ten light guides to thirty light guides. The cathetersherein can include one, two, three, four, five, six, seven, eight, nine,or ten light guides. The catheters can include 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 light guides.It will be appreciated that catheters herein can include any number oflight guides that can fall within a range, wherein any of the forgoingnumbers can serve as the lower or upper bound of the range, providedthat the lower bound of the range is a value less than the upper boundof the range. In some embodiments, the catheters herein can include morethan 30 light guides. The catheter 101 can further include a manifold114 at the proximal portion 104 that include one or more proximal endopenings that can accommodate one or more light guides, such as firstlight guide 110, a guidewire 126, and/or an inflation conduit 112. Thecatheter system 100 can include an inflator 118 configured to provideinflation of the balloon 122. Suitable balloon inflation pressures forballoon 122 will be described in more detail elsewhere herein.

Catheter 101 can include a longitudinal length 128. The catheters hereinwill have a longitudinal axis along the elongate shaft and short axisabout its circumference. The length of the catheters herein can includethose having a length of from 50 cm to 175 cm. In some embodiments, thelength of the catheters herein can include those having a length of from100-160 cm. In some embodiments, the length of the catheters herein caninclude those having a length of 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 100cm, 110 cm, 120 cm, 125 cm, 130 cm, 140 cm, 150 cm, 160 cm, 170 cm, or175 cm. It will be appreciated that the catheters herein can have ausable length that can fall within a range, wherein any of the forgoinglengths can serve as the lower or upper bound of the range, providedthat the lower bound of the range is a value less than the upper boundof the range.

Examples of the catheters in accordance with the various embodimentsherein include those having multiple light guides disposed about theelongate shaft at different positions around the circumference, as shownin FIGS. 2-5 . Referring now to FIG. 2 , a schematic cross-sectionalview of a catheter 101 of FIG. 1 along line 2-2′ in FIG. 1 is shown inaccordance with various embodiments herein. Catheter 101 includes anelongate shaft 102, a first light guide 210 and a second light guide 212separated by about 180 degrees around the circumference. The first lightguide 210 includes a side surface portion 216 that can include anysurface portion about the circumference of the first light guide. Thesecond light guide 212 includes a side surface portion 214 that caninclude any surface portion about the circumference of the second lightguide. In some examples, the side surface portion spans a portion of thecircumference of the light guides herein, such that it is less thancylindrical. In other examples, the side surface portion can span theentire circumference of the light guides herein such that it iscylindrical. It will be appreciated that any light guide describedherein can include a side surface portion about the circumference of thelight guide.

Referring now to FIGS. 3-5 , schematic cross-sectional views ofadditional configurations for catheters having multiple light guides areshown in accordance with various embodiments herein. The configurationof catheter 300 in FIG. 3 includes an elongate shaft 102, a first lightguide 310, a second light guide 312, and a third light guide 314separated by about 120 degrees around the circumference. Theconfiguration of catheter 400 in FIG. 4 includes an elongate shaft 102,a first light guide 410, a second light guide 412, a third light guide414, and a fourth light guide 416 separated by about 90 degrees aroundthe circumference. The configuration of catheter 500 shown in FIG. 5includes an elongate shaft 102, a first light guide 510, a second lightguide 512, a third light guide 514, a fourth light guide 516, a fifthlight guide 518, and a sixth light guide 520 separated by about 60degrees around the circumference. It will be appreciated that more thansix light guides can be used in the embodiments herein. It will befurther appreciated that the light guides can be disposed uniformly ornonuniformly about the elongate shaft.

The light guides described herein can further include one or morediverting features (not shown in FIG. 1 ) within the light guide todirect light toward a side surface portion of the distal portion of thelight guide and toward the balloon wall. A diverting feature can includeany feature of the system herein that diverts light from the light guideaway from its axial path toward a side surface portion of the lightguide. It will be appreciated that a light guide, such as first lightguide 110 of FIG. 1 , can include a first diverting feature configuredto direct light to exit from the first light guide 110 toward a sidesurface portion of the distal portion 106 of the first light guide 110and toward the balloon wall. The first light guide 110 can furtherdefine at least a first light window (not shown in FIG. 1 ) disposedalong the first light guide and in optical communication with the firstfiber diffuser. A catheter having a second light guide can include asecond diverting feature within the second light guide that isconfigured to direct light to exit from the second light guide toward aside surface portion of the distal portion of the second light guide andtoward the balloon wall. The second light guide can further define atleast a second light window disposed along the second light guide and inoptical communication with the second fiber diffuser.

In some embodiments herein, the light guides can include multiplediverting features. By way of example, each light guide herein caninclude a first diverting feature, a second diverting feature, a thirddiverting feature or a fourth diverting feature. In other embodiments,each light guide can include more than four diverting features. Thediverting features can be configured to direct light to exit a lightguide at a side surface portion thereof toward the balloon wall. In someexamples, the diverting feature directs light toward the balloon surfaceclosest to the diverting feature, so that the light does not cross thelongitudinal axis of the catheter on its path to the balloon surface. Itwill be appreciated that the diverting features can be in opticalcommunication with corresponding light window.

The diverting features herein can be configured to direct light in thelight guide toward a side surface portion of the distal portion, wherethe side surface portion is in optical communication with a lightwindow. It will be appreciated that the light guides herein can eachinclude multiple diverting features and multiple light windows. Examplesof the diverting features suitable for use herein include a reflectingelement, a refracting element, and a fiber diffuser, and will bediscussed in more detail below. In some embodiments, the divertingfeature can be a reflecting element. In some embodiments, the divertingfeature can be a refracting element. In some embodiments, the divertingfeature can be a fiber diffuser. Diverting features will be discussed inmore detail below and in reference to FIGS. 6-9 .

Catheter Embodiments (FIGS. 6-9)

In some embodiments, the diverting features within the catheters hereincan be included within the light guide at one or more regions of thedistal portion. Referring now to FIG. 6 a schematic cross-sectional viewof light guide 600 is shown in accordance with various embodimentsherein. Light guide 600 includes a plurality of diverting features, suchas fiber diffusers including first, second, and third fiber diffusers602, 604, and 606, respectively, positioned along the elongate shaft ofthe distal portion of the light guide 600. Each fiber diffuser directslight 601 from the light guide 600 to exit the light guide 600 at a sidesurface portion 622 thereof. Any side surface portion of the light guide600 can be in optical communication with one or more light windows, suchthat the fiber diffusers and the light windows are in opticalcommunication with one another.

By way of example, light guide 600 includes a plurality of light windowsincluding first, second, and third light windows 608, 610, and 612,respectively, positioned along the elongate shaft of the light guide600. The first, second, and third light windows 608, 610, and 612,respectively, can be in optical communication with the first, second,and third fiber diffusers 602, 604, and 606, respectively, at a sidesurface portion 622 of light guide 600. Light 601 within each of thefirst, second, and third fiber diffusers 602, 604, and 606 is directedto exit the light guide 600 at a side surface portion 622 and out thelight guides via the first, second, and third light windows 608, 610,and 612, respectively. The light windows 608, 610, and 612 of lightguide 600 can be axially spaced apart with at least one interveningnon-emitting portion 620 of the light guide 600 disposed between theplurality of light windows. The side surface portion 622 of the lightguide 600 can be a cylindrical side surface portion.

The light can exit the light windows to provide sub-millisecond pulsesof light from the light source through the at least the first, second,and third light windows 608, 610, and 612, thereby inducing plasmaformation in a balloon fluid, causing rapid bubble formation, andimparting pressure waves upon the treatment site. Plasma and bubbleformation is depicted in FIG. 6 as bubbles 614 in proximity to the lightwindows 608, 610, and 612. It will be appreciated that bubbles 614 canform around the entire circumferences of the light guide within a volumeof the balloon fluid at or adjacent to the light windows 608, 610, and612.

The fiber diffusers and light windows shown in FIG. 6 include thosehaving a cylindrical shape. By way of example, the fiber diffusers 602,604, and 606 are configured to span the entire circumference of lightguide 600, and as such, the fiber diffusers 602, 604, and 606 arecylindrical fiber diffusers. The light windows 608, 610, and 612 areconfigured to span the entire circumference of light guide 600, and assuch, light windows 608, 610, and 612 are cylindrical transducers. Itwill be appreciated that the cylindrical fiber diffusers 602, 604, and606 and cylindrical light windows 608, 610, and 612 can generate aplasma within a volume of the balloon fluid at or adjacent to each ofthe light windows 608, 610, and 612, and thus induce bubble formationand collapse, about the circumference of the light guide 600.

It will be appreciated that multiple light guides, each having one ormore diverting features, such as fiber diffusers, and one or more lightwindows can be used with the catheters herein. In some embodiments, thecatheters can include a first light guide, a second light guide, a thirdlight guide, and a fourth light guide. In other embodiments, thecatheters can include more than four light guides. In an embodimenthaving four light guides, the distal portion of a first light guide caninclude a plurality of light windows including a first light window, anda plurality of fiber diffusers including a first fiber diffuser. Thedistal portion of a second light guide can include a plurality of lightwindows including a second light window, and a plurality of fiberdiffusers including the second fiber diffuser. The distal portion of athird light guide can include a plurality of light windows including athird light window, and a plurality of fiber diffusers including a thirdfiber diffuser. The distal portion of a fourth light guide can include aplurality of light windows including a fourth light window, and aplurality of fiber diffusers including the fourth fiber diffuser. Eachfiber diffuser can direct light from each light guide to exit the lightguide at a side surface portion of the light guide toward the balloonwall.

The plurality of light windows can be spaced apart along thelongitudinal axis of the light guides or axially along the short axisabout the circumference of the light guides. In some embodiments, theplurality of light windows can be axially spaced apart with at least oneintervening non-emitting portion of the light guide disposed betweeneach of the plurality of light windows. In some embodiments, theplurality of light windows can be longitudinally spaced apart with atleast one intervening non-emitting portion of the light guide disposedbetween each of the plurality of light windows. In yet otherembodiments, the light window can span the length of the vascular lesionto be treated.

In some embodiments, the catheters herein can include divertingfeatures, such as fiber diffusers, in combination with one or morefocusing elements included within the light guide at one or more regionsof the distal portion. Referring now to FIG. 7 a schematiccross-sectional view of light guide 700 is shown in accordance withvarious embodiments herein. Light guide 700 includes a plurality offiber diffusers including a first fiber diffuser 702 and a second fiberdiffuser 704 positioned along the longitudinal axis of the distalportion of the light guide 700. Each fiber diffuser directs light 701from the light guide 700 to exit the light guide 700 at a side surfaceportion 722 thereof. The side surface portion 722 of the light guide 700can be a cylindrical side surface portion.

The first fiber diffuser 702 can be in optical communication with afirst light window 706, and the second fiber diffuser 704 can be inoptical communication with a second light window 708. The light guide700 can further include a refracting element 710 configured to focus thelight 701 away from the distal tip of the light guide 700 such that theinduced plasma formation occurs at a distance 712 away from the distaltip of the light guide 700 and within the balloon fluid, causing rapidbubble formation and imparting pressure waves at a treatment site. Thelight 701 within light guide 700 can exit the first light window 706 andthe second light window 708 to deliver sub-millisecond pulses of lightfrom the light source thereby inducing plasma formation in a volume ofballoon fluid at or near the first light window 706 and second lightwindow 708, causing rapid bubble formation, and imparting pressure wavesupon the treatment site. Plasma and bubble formation is depicted in FIG.7 as bubbles 714 in proximity to the light windows 706 and 708.

The fiber diffusers and light windows shown in FIG. 7 include thosehaving a cylindrical shape. By way of example, the fiber diffusers 702and 704 are configured to span the entire circumference of light guide700, and as such, the fiber diffusers 702 and 704 are cylindrical fiberdiffusers. The light windows 706 and 708 are configured to span theentire circumference of light guide 700, and as such, light windows 706and 708 are cylindrical transducers. It will be appreciated that thecylindrical fiber diffusers 702 and 704 and cylindrical light windows706 and 708 can generate plasma, and thus bubble formation, about thecircumference of the light guide 700.

The light guide 700 shown in FIG. 7 also includes a diverting feature,such as a refracting element 710 having a convex surface configured torefract the light 701 a distance 712 away from the distal portion of thelight guide 700 and to a first location 718. In some embodiments, thefirst location 718 is spaced away from the distal tip and is centered ona longitudinal axis of the first light guide. In other embodiments, thefirst location 718 is spaced away from the longitudinal axis of thefirst light guide, or off of the longitudinal axis. The divertingfeature suitable for focusing light away from the tip of the lightguides herein can include, but are not to be limited to, those having aconvex surface, a gradient-index (GRIN) lens, and a mirror focus lens.Focused plasma formation is depicted in FIG. 7 as focal bubble 716 at adistance 712 from the distal portion of the light guide 700.

The light guides herein can include one or more diverting featuresdisposed on one side portion of the distal portion to provide multipleselected regions within the light guide for the generation of pressurewaves. A diverting feature can be included as a part of the light guidethat diverts light away from its axial path through the light guide andto a side surface portion and toward a vessel wall. Referring now toFIG. 8 a schematic cross-sectional view of light guide 800 is shown inaccordance with various embodiments herein. Light guide 800 includes aplurality of diverting features including a first, second, and thirddiverting features 802, 804, and 806 positioned along a portion of theelongate shaft of the distal portion of the light guide 800. Eachdiverting feature directs light 801 from the light guide 800 to exit thelight guide 800 at a side surface portion 822 thereof. The side surfaceportion 822 of the light guide 800 can be in optical communication withone or more diverting features and one or more light windows, such thatthe diverting features and one or more light windows are in opticalcommunication with one another.

By way of example, light guide 800 includes a plurality of light windowsincluding a first, second, and third light windows 808, 810, and 812positioned along the elongate shaft of the light guide 800. The first,second, and third light windows 808, 810, and 812 can be in opticalcommunication with the first, second, and third diverting features 802,804, and 806, respectively, at a side surface portion 822 of light guide800. Light within each of the first, second, and third divertingfeatures 802, 804, and 806 is directed to exit the light guide 800 at aside surface portion 822 and pass through first, second, and third lightwindows 808, 810, and 812, respectively. The light can exit the lightwindows to provide sub-millisecond pulses of light from the light sourcethrough the at least first light window and second light window, therebyinducing plasma formation in a balloon fluid, causing rapid bubbleformation, and imparting pressure waves upon the treatment site. Plasmaand bubble formation is depicted in FIG. 8 as bubbles 814 in proximityto the light windows 808, 810, and 812. The light windows 808, 810, and812 of light guide 800 can be axially spaced apart with at least oneintervening non-emitting portion 820 of the light guide 800 disposedbetween the plurality of light windows.

In various examples, the light windows, diverting features, or both canvary in size and shape along the length of the catheter. In variousexamples, the light windows, diverting features, or both can bedome-shaped, square, triangular, circular, rectangular, and the like,and can increase in size moving toward the distal portion. In theexample of FIG. 8 , the most proximal first diverting feature 802 issmaller than the second diverting feature 804, and the third divertingfeature 806 is larger than the second diverting feature 804. In theexample of FIG. 8 , the most proximal first light window 808 is smallerin surface area than the second light window 810, and the third lightwindow 812 is larger in surface area than the second light window 810.

While the light windows and diverting features of light guide 800 areshown disposed on one side portion of light guide 800, it will beappreciated that the light windows and diverting features can bedisposed in many different positions along the elongate shaft. Invarious examples, light windows and diverting features can be disposedopposite one another along the elongate shaft of the light guide.Referring now to FIG. 9 , a schematic cross-sectional view of lightguide 900 is shown in accordance with various embodiments herein. Lightguide 900 includes diverting features 902, 904, 906, and 908. Eachdiverting feature directs light 901 from the light guide 900 to exit thelight guide 900 at a side surface portion 922 thereof. The side surfaceportion 922 of the light guide 900 can be a cylindrical side surfaceportion. The side surface portion 922 of the light guide 900 can be inoptical communication with one or more diverting features and one ormore light windows, such that the diverting features and light windowsare in optical communication with one another.

By way of example, light guide 900 includes a plurality of light windowsincluding a first, second, third, and fourth light windows 910, 912,916, and 918, respectively, positioned along the elongate shaft of thelight guide 900. The first, second, third, and fourth light windows 910,912, 916, and 918, respectively, can be in optical communication withthe first, second, third, and fourth diverting features 902, 904, 906,and 908, respectively, at a plurality of side surface portion 922 oflight guide 900. Light within each of the first, second, third, andfourth diverting features 902, 904, 906, and 908 is directed to exit thelight guide 900 at a side surface portion 922 and exits through thefirst, second, third, and fourth light windows 910, 912, 916, and 918,respectively. Light energy can exit light windows 910, 912, 916, and 918and induce plasma formation in a volume of balloon fluid at or near thelight windows 910, 912, 916, and 918, causing rapid bubble formation,and imparting pressure waves upon the treatment site. Plasma and bubbleformation is depicted in FIG. 9 as bubbles 914 in proximity to the lightwindows 910, 912, 916, and 918. The light windows 910, 912, 916, and 918of light guide 900 can be axially spaced apart with at least oneintervening non-emitting portion 920 of the light guide 900 disposedbetween the plurality of light windows.

The catheters described herein can be used in one or more methods forgenerating pressure waves to induce fractures in a vascular lesionwithin or adjacent a vessel wall of a blood vessel. Referring now toFIG. 10 , a schematic flow diagram for a method 1000 is shown inaccordance with the various embodiments herein. Method 1000 includesadvancing a catheter 1010 to a treatment site 1014 within the bloodvessel 1012, the catheter 1010 including an elongate shaft 102, and aballoon 122 coupled to the elongate shaft 102 at 1002. In someembodiments, the treatment site 1014 can include a vascular lesionlocation within a patient's vasculature. In some embodiments, thevascular lesion can include a calcified vascular lesion or a fibrousvascular lesion.

The method 1000 includes expanding the balloon 122 from a collapsedconfiguration 1002 suitable for advancing the catheter 1010 through apatient's vasculature to a first expanded configuration 1004 suitablefor anchoring the catheter in position relative to the treatment site1014. The method 1000 includes, after expanding the balloon 122 to thefirst expanded configuration 1004, activating a light source in opticalcommunication with each of the first light guide and the second lightguide to provide sub-millisecond pulses of light from the light sourceto the at least first diverting feature and second diverting feature,thereby initiating plasma formation in a balloon fluid, causing rapidbubble formation, and imparting pressure waves 1016 upon the treatmentsite 1014.

In some embodiments, the method 1000 includes a first light guide havinga first diverting feature configured to direct light to exit from thefirst light guide toward a side surface portion of the distal portion ofthe first light guide and toward the balloon wall, where the first lightguide defines a first light window in optical communication with thefirst diverting feature.

In some embodiments, the method 1000 includes a second light guidehaving a second diverting feature configured to direct light to exitfrom the second light guide toward a side surface portion of the distalportion of the second light guide and toward the balloon wall, where thesecond light guide defines a second light window in opticalcommunication with the second diverting feature.

In some embodiments, the method 1000 includes a third light guide havinga third diverting feature configured to direct light to exit from thethird light guide toward a side surface portion of the distal portion ofthe third light guide and toward the balloon wall, where the third lightguide defines a third light window in optical communication with thethird diverting feature.

In some embodiments, the method 1000 includes a fourth light guidehaving a fourth diverting feature configured to direct light to exitfrom the fourth light guide toward a side surface portion of the distalportion of the fourth light guide and toward the balloon wall, where thefourth light guide defines a fourth light window in opticalcommunication with the fourth diverting feature. In some embodiments,the method 1000 includes more than four light guides.

The method 1000 can also include further expanding the balloon 122 fromthe first expanded configuration 1004 to a second further expandedconfiguration 1006. The method can include completely removing thecatheter 1010 from the patient's vasculature at 1008.

The light guides and components associated therewith that are suitableto be used in the methods herein can be activated in various ways toprovide a treatment to a treatment site. In some embodiments, each lightguide can be activated simultaneously. In some embodiments, each lightguide can be activated sequentially. By way of example, if two lightguides are present, they can each be activated at the same time, theycan be activated one after the other sequentially, or they can beactivated in alternating pairs or another alternating fashion. The lightguides can be activated once or multiple times during the course of atreatment. In an embodiment with four light guides, each of the fourlight guides can be activated at the same time, sequentially, in pairs,or in alternating pairs. By way of example, if four light guides arepresent, each with one light window, the first and third light guide andtheir respective light windows can form a pair that can be activatedfollowed by activation of the second and fourth light guide and theirrespective light windows that can form a pair, either once each or in anongoing alternating fashion. It will be appreciated that manyconfigurations exist for activating multiple light guides and theirrespective light windows in accordance with the embodiments herein.

Vascular lesions can be present within or about a vessel wall of a bloodvessel in various configurations, including surrounding the entire lumenof the vessel or surrounding a portion of the lumen of a vessel.Vascular lesions can also be present in various shapes and sizes. Toprovide targeted therapy to a vascular lesion, the light guides hereincan be configured to be activated depending on the vascular lesionlocation, shape, and size. By way of example, if a vascular lesion islocated partially about the circumference of a blood vessel, the lightguides can be activated partially about the circumference of thecatheter to match the location, size, and shape of the vascular lesion.In some embodiments, where the vascular lesion spans the entirecircumference of the blood vessel, the light guides herein can beactivated about the entire circumference of the blood vessel. In variousembodiments, the light guides can additionally be activated to match thelength and width of the vascular lesion.

The duration of the methods herein can vary according to the specifictreatment site and size of a vascular lesion. In some embodiments, thetotal treatment time can be from one second to thirty seconds. In someembodiments, the total treatment time can be from five seconds to twentyseconds. In other embodiments, the total treatment time can be from fiveseconds to ten seconds.

The sub-millisecond pulses of light can be delivered to a treatment siteat a frequency of from at least 1 hertz (Hz) to 5000 Hz. In someembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency from at least 30 Hz to 1000 Hz. In otherembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency from at least 10 Hz to 100 Hz. In yetother embodiments, the sub-millisecond pulses of light can be deliveredto a treatment site at a frequency from at least 1 Hz to 30 Hz. In someembodiments, the sub-millisecond pulses of light can be delivered to atreatment site at a frequency that can be greater than or equal to 1 Hz,2 Hz, 3 Hz, 4 Hz, 5 Hz, 6 Hz, 7 Hz, 8 Hz, or 9 Hz, 10 Hz, 20 Hz, 30 Hz,40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, 100 Hz, 200 Hz, 300 Hz, 400Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz, 900 Hz, 1000 Hz, 1250 Hz, 1500 Hz,1750 Hz, 2000 Hz, 2250 Hz, 2500 Hz, 2750 Hz, 3000 Hz, 3250 Hz, 3500 Hz,3750 Hz, 4000 Hz, 4250 Hz, 4500 Hz, 4750 Hz, or 5000 Hz or can be anamount falling within a range between any of the foregoing.

Optical Fiber Protection Configurations (FIGS. 11-18)

The catheter systems herein can include various configurations thatinclude one or more protection structures configured to providestructural protection to one or more portions of the light guides hereinwhen in the presence of the pressure waves. The catheter systemsutilizing protection structures can be suitable for imparting pressureto induce fractures in a vascular lesion within or adjacent a bloodvessel wall. Such catheter systems can include a catheter configured toadvance to the vascular lesion located within or adjacent a bloodvessel. In various configurations the catheters can include an elongateshaft and a balloon coupled to the elongate shaft. The balloon can beconfigured to be filled with balloon fluid and configured to expand fromthe collapsed configuration suitable for advancing the catheter througha patient's vasculature to a first expanded configuration suitable foranchoring the catheter in position relative to a treatment site. In theembodiments described herein, the elongate shaft can define a firstrecess. In some embodiments, the first recess can include a longitudinalrecess along a longitudinal surface of the elongate shaft. In someembodiments, the first recess can include a distal tip recess along alongitudinal surface of the elongate shaft. Referring now to FIG. 11 , aschematic side-view of a catheter 1100 including a protection structure,with a partial longitudinal cross-sectional view of a balloon 122, isshown in accordance with various embodiments herein.

The catheter 1100 can include a first light guide 1102 disposed alongthe elongate shaft 102 and within the balloon 122. The first light guide1102 can be configured to be placed in optical communication with alight source and a balloon fluid. It will be appreciated that the firstlight guide 1102 can include an optical fiber and the light source caninclude a laser, both of which are described in more detail elsewhereherein. The light source in communication with the light guides hereincan be configured to provide pulses of light 1112 to the balloon fluid,thereby initiating plasma formation in the balloon fluid, causing rapidbubble formation of bubble 1114, and imparting pressure waves upon thevascular lesion. The first light guide 1102 can include a longitudinalaxis 1108.

A first portion 1104 of the first light guide 1102 can extend into thefirst recess 1106. In some embodiments, the first portion 1104 includesa distal tip 1116 of the first light guide 1102. The catheter 1100 caninclude a first protection structure 1110 disposed within the firstrecess 1106 of the elongate shaft 102 and in contact with the firstportion 1104 of the light guide 1102. The first protection structure1110 can be configured to provide structural protection to the firstportion 1104 of the first light guide 1102. In some embodiments, thefirst protection structure 1110 can be configured to provide structuralprotection to the first portion 1104, when the first portion 1104 is adistal tip 1116 of a light guide. In other embodiments, the firstprotection structure 1110 can be configured to provide structuralprotection to the first portion 1104, when the first portion 1104 is alongitudinal portion of a light guide. The first protection structure1110 can be configured to provide structural protection to the firstportion 1104 of the first light guide 1102 in the presence of thepressure waves. In some examples, the first protection structure 1110includes a potting material filling the first recess 1106, where thepotting material is optically matched to the first light guide 1102. Itwill be appreciated that in some embodiments, the potting materialfilling the first recess 1106 is not optically matched and can serve asa diverting feature.

As the term is used herein, two materials are “optically matched” ifthose materials have indices of refraction that are the same whenexpressed to two decimal places. In other embodiments herein, twomaterials are not optically matched, or are “optically mismatched”, whenthe two materials that have indices of refraction that are differentwhen expressed to two decimal places.

The light guide 1102 of catheter 1100 can further include a firstdiverting feature 1118 selected from the group including at least one ofa reflecting element, a refracting element, or a fiber diffuser, as willbe discussed elsewhere herein. In various embodiments, the divertingfeature can include a fiber diffuser selected from a group including ofa machined portion of the light guide, a laser-machined portion of thelight guide, fiber Bragg gratings, a fused splicing forming at least oneinternal mirror, and a splicing of two or more diffuse regions. In someembodiments, diverting feature 1118 of catheter 1100 can include a fusedsplicing forming at least one internal mirror, where the first lightguide can include a first longitudinal light window 1120 disposed alonga longitudinal length of light guide and in optical communication withthe first diverting feature 1118.

It will be appreciated that the first portion of the light guides hereinthat extend into the recess defined by the elongate shaft can include apart of the light guide that extends into the recess, the entire portionof the light guide that extends into recess, or any portion thatoverlaps with or is present within the recess. In some examples,multiple portions of the light guides herein can extend into more thanone recess along the elongate shaft to form a second portion, a thirdportion, a fourth portion, and the like, of the light guide presentwithin a second recess, a third recess, a fourth recess, and the like.

Multiple recesses defined along the longitudinal length of the cathetersherein can be suitable for use with one or more light guides disposedalong the length of the elongate shaft to provide multiple locationswhere light can be directed from the light guides. Referring now toFIGS. 12 and 13 , schematic side-views of a portion of the elongateshaft of catheters 1200 and 1300 are shown in accordance to variousembodiments herein. In the configuration shown in FIG. 12 , elongateshaft 102 of catheter 1200 includes a first light guide 1202 and asecond light guide 1204. The elongate shaft 102 defines first recesses1210 and 1212, and second recesses 1206 and 1208, along the longitudinallength. First light guide 1202 extends into second recess 1206 and firstrecess 1210, such that a first portion 12164 of the first light guide1202 extends into first recess 1210 and a second portion 1214 of thefirst light guide 1202 extends into second recess 1206. Second lightguide 1204 extends into first recess 1212 and second recess 1208, suchthat a first portion 1220 of the second light guide 1204 extends intofirst recess 1212 and a second portion 1218 of the second light guide1204 extends into second recess 1208.

The second portion 1214 of the first light guide 1202 and the secondportion 1218 of the second light guide 1204 each extend through theentire length of the respective second recesses 1206 and 1208. The firstlight guide 1202 and the second light guide 1204 each extend intomultiple recesses. By way of example, the first portion 1216 of thefirst light guide 1202 and the first portion 1220 of the second lightguide 1204 each extend partially into the recesses first 1210 and 1212such that the first portion 1216 of the first light guide 1202 includesa distal tip of the first light guide 1202 and the first portion 1220 ofthe second light guide 1204 includes a distal tip of the second lightguide 1204. It will be appreciated that the first light guide 1202 andthe second light guide 1204 are depicted as being disposed 180 degreesabout the circumference of the elongate shaft, however, the first lightguide 1202 and the second light guide 1204 can be disposed about theelongate shaft in many configurations as discussed elsewhere herein.

In the configuration in FIG. 13 , elongate shaft 102 of catheter 1300includes a first light guide 1302, a second light guide 1304, and athird light guide 1305. While not shown in FIG. 13 , it will beappreciated that catheter 1300 can further include a fourth light guidedisposed 180 degrees about the circumference of the elongate shaft 102and opposite the third light guide 1305. In various embodiments,catheter 1300 can include more than four light guides. The elongateshaft 102 of catheter 1300 defines recesses 1306, 1308, and 1310, alongthe longitudinal length. First light guide 1302 extends into firstrecess 1306 such that a first portion 1314 of the first light guide 1302extends into first recess 1306. Second light guide 1304 extends intosecond recess 1308 such that a first portion 1316 of the second lightguide 1304 extends into second recess 1308. Third light guide 1305extends into third recess 1310 such that a first portion 1318 of thethird light guide 1305 extends into third recess 1310. The firstportions 1314, 1316, and 1318 of the first, second, and third lightguide each extend partially into their respective recesses 1306, 1308,and 1310. Each of the first portions 1314, 1316, and 1318 of the first,second, and third light guides 1302, 1304, and 1305 includes a distaltip portion within each recess.

The protection structures suitable for use herein can be tailored tovarious configurations dependent on if the portion of the light guide tobe protected is a distal tip or a longitudinal portion. Referring now tothe embodiments in FIGS. 14-18 , examples of several side views of anelongate shaft, with longitudinal cross-sectional views of theprotection structures, are shown in accordance with various embodimentsherein. In the configuration in FIG. 14 , catheter 1400 includes a firstportion 1404 of a first light guide 1402 that extends into a firstrecess 1406 defined by the elongate shaft 102. The catheter 1400 caninclude a first protection structure 1410 disposed within the firstrecess 1406 of the elongate shaft 102 and in contact with the firstportion 1404 of the light guide 1402. The first protection structure1410 can be an end cap disposed about the distal portion 1414 of thefirst portion 1404 of the light guide 1402. The end cap can be flushwith a distal tip 1408 o the light guide 1402. The first protectionstructure 1410 can be adhered to an outer surface of the distal portion1414 of the first portion 1404 of the light guide 1402 with an adhesive1412, where the adhesive 1412 and the end cap protection structure 1410are optically matched to the first light guide 1402. It will beappreciated that in some embodiments, the end cap protection structureis not optically matched.

In the configuration in FIG. 15 , catheter 1500 includes a first portion1504 of a first light guide 1502 that extends into a first recess 1506defined by the elongate shaft 102. The catheter 1500 can include a firstprotection structure 1510 disposed within the first recess 1506 of theelongate shaft 102 and in contact with the first portion 1504 of thelight guide 1502. The first protection structure 1510 can be a firstcomponent that is abutted against and fused to the distal tip 1508 ofthe first light guide 1502, where the first component protectionstructure 1510 is optically matched to the first light guide 1502. Invarious embodiments, the first component protection structure can bemade from glass, quartz, sapphire, diamond, and the like. It will beappreciated that in some embodiments, the first component protectionstructure is not optically matched.

In the configuration in FIG. 16 , catheter 1600 includes a secondportion 1604 of a first light guide 1602 that extends into a secondrecess 1606 defined by the elongate shaft 102. The second recess 1606can be disposed within a balloon along a longitudinal surface 1612 ofthe elongate shaft. A second portion 1604 of the first light guide 1602can extend into the second recess 1606, where the second portion 1604can define a longitudinal light window 1608 disposed along alongitudinal length of the second portion 1604 and in opticalcommunication with a first diverting feature 1614. The catheter 1600 canfurther include a longitudinal protection structure 1610 in contact withthe second portion 1604 of the first light guide 1602 and configured toprovide structural protection to the second portion 1604 in the presenceof pressure waves. The longitudinal protection structure 1610 can be asleeve disposed about the longitudinal light window 1608 and adhered tothe longitudinal surface of the second portion 1604 of the first lightguide 1602 with an adhesive (not shown), where the adhesive and thesleeve longitudinal protection structure 1610 are optically matched tothe first light guide 1602. In some embodiments, the second recess 1606can include a longitudinal recess along a longitudinal surface of theelongate shaft. It will be appreciated that in some embodiments, thesleeve longitudinal protection structure and adhesive are not opticallymatched.

In the configuration in FIG. 17 , catheter 1700 includes a secondportion 1704 of a first light guide 1702 that extends into a secondrecess 1706 defined by the elongate shaft 102. The second recess 1706can be disposed within a balloon along a longitudinal surface 1712 ofthe elongate shaft 102. A second portion 1704 of the first light guide1702 can extend into the second recess 1706, where the second portion1704 can define a longitudinal light window 1708 disposed along alongitudinal length of the second portion 1704 and in opticalcommunication with a first diverting feature 1714. The catheter 1700 canfurther include a longitudinal protection structure 1710 in contact withthe second portion 1704 of the first light guide 1702 and configured toprovide structural protection to the second portion 1704 in the presenceof pressure waves. The longitudinal protection structure 1710 can be apotting material disposed within the second recess 1706 and around thesecond portion 1704 of the first light guide 1702, where the pottingmaterial longitudinal protection structure 1710 is optically matched tothe first light guide 1702. It will be appreciated that in someembodiments, the potting material of the longitudinal protectionstructure 1710 is not optically matched and can serve as a divertingfeature.

In the configuration in FIG. 18 , catheter 1800 includes a secondportion 1804 of a first light guide 1802 that extends into a secondrecess 1806 defined by the elongate shaft 102, and also includes adistal tip 1816 of a second light guide 1808. The second recess 1806 canbe disposed within a balloon along a longitudinal surface 1812 of theelongate shaft 102. The catheter 1800 can include a longitudinalprotection structure 1810 in contact with the proximal tip 1814 of asecond portion 1804 of the first light guide 1802 and the distal tip1816 of the second light guide 1808. The longitudinal protectionstructure 1810 can be a first component fused between the proximal tip1814 of the second portion 1804 of the first light guide 1802 and thedistal tip 1816 of the second light guide 1808. The fused componentlongitudinal protection structure 1810 can be configured to providestructural protection to the proximal tip 1814 of the second portion1804 of the first light guide 1802 and the distal tip 1816 of the secondlight guide 1808 in the presence of pressure waves. The second lightguide 1808 can extend in a distal direction into the second recess 1806and comprises a distal tip 1816 disposed in the second recess 1806. Thefirst light guide 1802 can extend in a proximal direction into thesecond recess 1806 and includes a proximal tip 1814. The first componentlongitudinal protection structure 1810 can be abutted against and fusedto the distal tip 1816 of the second light guide 1808 and the proximaltip 1814 of the second portion 1804 of the first light guide 1802, wherethe first component is optically matched to the first and second lightguides, 1802 and 1808. It will be appreciated that in some embodiments,the first component is not optically matched and can serve as adiverting feature.

It will be appreciated that the balloons, light guides, and elongateshafts suitable for use with the protection structures can include anyof those described elsewhere herein. In various embodiments, theelongate shaft defines an inflation lumen, where the inflation lumen isin fluid communication with the balloon at a distal portion of theelongate shaft.

In an example, a catheter system for imparting pressure to inducefractures in a vascular lesion within or adjacent a blood vessel wall isprovided. The catheter system can include a catheter configured toadvance to the vascular lesion located within or adjacent a bloodvessel. The catheter can include an elongate shaft and a balloon coupledto the elongate shaft. The balloon can be configured to be filled withballoon fluid and configured to expand from a collapsed configurationsuitable for advancing the catheter through a patient's vasculature to afirst expanded configuration suitable for anchoring the catheter inposition relative to a treatment site. The elongate shaft can define afirst recess within the balloon. The catheter can include a first lightguide disposed along the elongate shaft and within the balloon, thefirst light guide configured to be placed in optical communication witha light source and a balloon fluid. A first portion of the first lightguide can extend into the first recess and can include a distal tip ofthe first light guide. The catheter can also include a first protectionstructure disposed within the first recess of the elongate shaft and incontact with the first portion of the light guide, where the firstprotection structure includes a potting material filling the firstrecess, where the potting material is optically matched to the firstlight guide. It will be appreciated that in some embodiments, the firstprotection structure is not optically matched.

The catheter system can include a light source that is configured toprovide pulses of light to the balloon fluid, thereby initiating plasmaformation in the balloon fluid, causing rapid bubble formation, andimparting pressure waves upon the vascular lesion. The first protectionstructure can be configured to provide structural protection to thefirst portion and distal tip of the first light guide in the presence ofthe pressure waves. In some embodiments, the first protection structurecan include a potting material that fills the first recess and includesa potting material outer surface that is flush with an outer surface ofthe elongate shaft. In some embodiments, the first protection structurecan include a potting material that partially fills the first recess andincludes a potting material outer surface that is not flush with theouter surface of the elongate shaft. In yet other embodiments, the firstprotection structure can include a potting material that over fills thefirst recess and includes a potting material outer surface that forms adome-shaped surface that extends past an outer surface of the elongateshaft, and in some embodiments the dome-shaped surface of the pottingmaterial can act as a focusing element.

The various protection structures described herein can include, but arenot to be limited to, end cap protection structures, sleeve protectionstructures, potting material protection structures, and fused componentprotection structures. The protection structures can be configured toprotect a portion of a light guide that can include a distal tip, alongitudinal portion, or both. In one embodiment for protection of adistal tip, an end cap protection structure can include an annularcylinder shape about a distal tip of a light guide. In one embodiment,the distal tip of the first light guide can be flush with a distal tipof the end cap and not obstructed by the end cap. In other embodiments,the distal tip of the first light guide can be flush with a distal tipof the end cap and covered by an optically matched material. In anotherembodiment for protection of a distal tip, a protection structures thatincludes potting material can be used to cover the entire outer surfaceof a distal tip. In various embodiments, the potting material can fillthe recess so that an outer surface of the potting material iscontinuous with an outer surface of the elongate shaft. In someembodiments, a potting material can completely surround a distal tip ofthe first light guide. In other embodiments, a potting material canpartially surround a distal tip of the first light guide. In yet anotherembodiment for protecting a distal tip, the protection structures caninclude fused components, where the fused component can include a solidcylindrical shape. In some embodiments, the fused component material canbe harder and more durable than the material of the light guides herein.In some embodiments, the fused component can include a material such asa glass, sapphire, diamond, and the like.

Various examples of protection structures suitable for protecting alongitudinal portion of a light guide disposed in a recess can include asleeve, a potting material, and a fused component. In one embodiment forprotection of longitudinal portion of a light guide, a sleeve protectionstructure can include an annular cylinder shape disposed about alongitudinal portion of a light guide. In various embodiments, thepotting material can fill the recess so that an outer surface of thepotting material is continuous with an outer surface of the elongateshaft. In some embodiments, a potting material can completely surround alongitudinal portion of the first light guide. In other embodiments, apotting material can partially surround a longitudinal portion of thefirst light guide. In some embodiments, the potting material can fill arecess and include a potting material outer surface that is flush withthe outer surface of the elongate shaft. In some embodiments, thepotting material can partially fill a recess and include a pottingmaterial outer surface that is not flush with the outer surface of theelongate shaft. In yet other embodiments, the potting material can overfill a recess and include a potting material outer surface that forms adome-shaped surface that extends past an outer surface of the elongateshaft, and in some embodiments the dome-shaped surface can act as afocusing element. In yet another embodiment for protecting alongitudinal portion, the protection structures can include fusedcomponents, where the fused component can include a solid cylindricalshape disposed between two light guides. In some embodiments, the fusedcomponent material can be harder and more durable than the material ofthe light guides herein. In some embodiments, the fused component caninclude a material such as a glass, sapphire, diamond, and the like. Insome examples, the first longitudinal protection structure is completelywithin the first longitudinal recess. In some examples, the firstlongitudinal protection structure protrudes from the first longitudinalrecess.

The light guides including protection structures as described can beused in various methods for generating pressure waves to inducefractures in a vascular lesion within or adjacent a vessel wall of ablood vessel. In one embodiment, the method can include advancing acatheter to a vascular lesion within the blood vessel, where thecatheter includes an elongate shaft, a balloon coupled to the elongateshaft, and at least a first light guide disposed along the elongateshaft within the balloon. The first light guide can be configured to beplaced in optical communication with a light source and a balloon fluid.A first portion of the first light guide can be disposed within a firstrecess defined by the elongate shaft, where the first portion of thefirst light guide can be in contact with a first light guide protectionstructure. The method can include expanding the balloon from a collapsedconfiguration suitable for advancing the catheter through a patient'svasculature to a first expanded configuration suitable for anchoring thecatheter in position relative to a vascular lesion. The method caninclude, after expanding the balloon, activating a light source inoptical communication with the first light guide to direct light fromwithin the first light guide to initiate plasma formation in the balloonfluid and to cause rapid bubble formation, thereby imparting pressurewaves upon the vascular lesion, wherein the first light guide protectionstructure is configured to provide structural protection to the distaltip in the presence of the pressure waves. In some embodiments, themethod can include catheters where the first portion includes a distaltip of the first light guide, and where the first protection structurecan be configured to provide structural protection to the distal tip ofthe first light guide. In various embodiments, the method can include,after activating the light source, further expanding the balloon fromthe first expanded configuration to a second further expandedconfiguration.

Focusing Element Configurations (FIGS. 19-21)

The catheter systems herein can include various focusing elements todirect light from within a light guide to a location away from the lightguide. Light directed to a location away from the light guide caninitiate a plasma formation within a balloon fluid at the location. Thecatheter systems including focusing elements are designed to impartpressure to induce fractures in a vascular lesion within or adjacent ablood vessel wall. Beneficial therapy effects may be enjoyed byinitiating the plasma formation at a location away from the light guideinstead of immediately adjacent to the light guide. The light guide maybe less likely to be damaged by the plasma initiation event, theresulting pressure, or the resulting bubble dynamics if the plasmaformation location is at a location away from the light guide ratherthan immediately adjacent to the light guide.

As discussed elsewhere herein, the catheter systems can include acatheter that can be configured to advance to the vascular lesionlocated within or adjacent a blood vessel. The catheter can include anelongate shaft and a balloon coupled to the elongate shaft. The ballooncan include a balloon wall and it can be configured to expand from acollapsed configuration suitable for advancing the catheter through apatient's vasculature to a first expanded configuration suitable foranchoring the catheter in position relative to a vascular lesion. Thecatheters herein can include a first light guide disposed along theelongate shaft and within the balloon, where the first light guide canbe configured to be placed in optical communication with a light sourceand a balloon fluid. It will be appreciated that the first light guidecan include an optical fiber and the light source can include a laser,both of which are described in more detail elsewhere herein.

The first light guide can include at least a first focusing elementlocated at a distal portion of the first light guide within a balloonand in optical communication with the light source. Referring now toFIG. 19 , a schematic side-view of a catheter 1900, with a partiallongitudinal cross-sectional view of a balloon, is shown in accordancewith various embodiments herein. Catheter 1900 includes an elongateshaft 102, a balloon 122, and a first light guide 1902 disposed alongthe elongate shaft 102 and within the balloon 122. The first light guide1902 can be configured to be in optical communication with a lightsource at its proximal end and with a balloon fluid at its distal end.In some embodiments, the distal portion of the first light guide caninclude a distal tip of the first light guide. In other embodiments, thedistal portion of the first light guide can include a longitudinalportion thereof. The elongate shaft 102 of catheter 1900 can define aninflation lumen (not shown), where the inflation lumen can be in fluidcommunication with the balloon 122 at a distal portion of the elongateshaft 102.

In the configuration shown in FIG. 19 , the first light guide 1902includes a distal tip 1904, and a first focusing element 1906 disposedat the distal tip 1904. The first light guide 1902 can include alongitudinal axis 1908. The first focusing element 1906 can beconfigured to direct light 1910 from within the first light guide 1902to a first location 1912 at a first distance 1914 away from the distaltip 1904 of the first light guide 1902. Light directed to the firstlocation 1912 can initiate plasma formation in the balloon fluid awayfrom the distal tip 1904 and to cause rapid bubble formation, therebyimparting

pressure waves upon the vascular lesion. The first location 1912 can bespaced away from the distal tip 1904 and centered on a longitudinal axis1908 of the first light guide 1902. The formation of plasma and bubble1916 within the balloon fluid can originate at the first location 1912at a first distance 1914 spaced away from the distal tip 1904 andcentered on a longitudinal axis 1908 of the first light guide 1902. Thefirst light guide 1902 can also include a first diverting feature (notshown) in optical communication with the focusing element and located ata distal portion of the first light guide, where the diverting featureis configured to direct light from within the first light guide toward afirst focusing element and toward the balloon wall away from, or off of,the longitudinal axis.

In some embodiments, the first light guide 1902 can include a secondfocusing element located at a distal portion of the first light guide,where the second focusing element can be configured to direct light fromwithin the first light guide to a second location at a second distanceaway from the distal portion of the first light guide to initiate plasmaformation in the balloon fluid away from the distal portion and to causerapid bubble formation, thereby imparting pressure waves upon thevascular lesion. The second focusing element may also be located on thedistal tip along with the first focusing element 1906, such as theembodiment described with respect to FIG. 20 . The second focusingelement may also be located along a longitudinal surface of the lightguide, similar to one of the focusing elements shown in the embodimentof FIG. 21 .

In addition or alternatively, in other embodiments, catheter 1900 caninclude a second light guide coupled to the elongate shaft. The secondlight guide can be in optical communication with a light source and aballoon inflation fluid, where the second light guide can be in opticalcommunication with the light source and the balloon inflation fluid. Thesecond light guide can include a focusing element of the second lightguide located at a distal portion of the second light guide and inoptical communication with the light source. The focusing element of thesecond light guide can be configured to direct light from within thesecond light guide to a second location at a second distance from thedistal portion of the second light guide to initiate plasma formation inthe balloon fluid away from the distal portion and to cause rapid bubbleformation, thereby imparting pressure waves upon the vascular lesion. Itwill be appreciated that multiple light guides, each having multiplefocusing elements, can be used in the catheter systems herein.

The focusing elements herein can direct light from within a light guideto one or more locations at a distance of at least 1 micrometers (μm)and at most 1 millimeters (mm) away from the distal tip of the firstlight guide. In an embodiment, the focusing elements herein can directlight from within a light guide to one or more locations at a distanceof at least 10 μm and at most 1 mm away from the distal tip of the firstlight guide. In some embodiments, the focusing elements herein candirect light from within a light guide to a distance of greater than orequal to 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 200 μm, 300μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1 mm, 2 mm, 3 mm, 4mm, or 5 mm, away from the distal tip of the first light guide, or canbe an amount falling within a range between any of the foregoing. Insome embodiments, the focusing elements herein can direct light fromwithin a light guide to one or more locations at a distance greater than1 mm.

The light guides suitable for use in the catheter systems herein caninclude multiple focusing elements in a distal portion, as will bediscussed in reference to FIGS. 20 and 21 . In the configuration in FIG.20 , a longitudinal cross-sectional view of light guide 2000 is shown inaccordance with various embodiments herein. The light guide 2000 can bedisposed along an elongate shaft of a catheter and placed in opticalcommunication with a light source and a balloon fluid. The light guide2000 can include a distal portion, where the distal portion can be adistal tip 2002. Light guide 2000 can further include a first focusingelement 2004 and a second focusing element 2006. In the example of FIG.20 , both the first focusing element 2004 and the second focusingelement 2006 are located at the distal tip 2002 of the light guide 2000.The first focusing element 2004 can be configured to direct light 2010from within the light guide 2000 to a first location 2016 at a firstdistance 2012 spaced away from the longitudinal axis 2008 of the lightguide 2000 to initiate plasma formation in the balloon fluid at thefirst location 2016. Formation of plasma at the first location 2016 cancause rapid bubble formation of bubble 2020, thereby imparting pressurewaves upon the vascular lesion. The second focusing element 2006 can beconfigured to direct light 2010 from within the light guide 2000 to asecond location 2018 at a second distance 2014 spaced away from thelongitudinal axis 2008 of the light guide 2000 to initiate plasmaformation in the balloon fluid away at the second location 2018.Formation of plasma at the second location 2018 can cause rapid bubble2022 formation, thereby imparting pressure waves upon the vascularlesion. In the embodiment shown in FIG. 20 , the first distance 2012 isequal to or approximately equal to the second distance 2014, the firstlocation 2016 is off-axis in one direction, and the second location 2018is off-axis in a different direction. In some embodiment, the firstdistance 2012 is not equal to the second distance 2014.

In the configuration in FIG. 21 , a longitudinal cross-sectional view oflight guide 2100 is shown in accordance with various embodiments herein.The light guide 2100 can be disposed along an elongate shaft of acatheter and placed in optical communication with a light source and aballoon fluid. The light guide 2100 can include a distal portion, suchas a longitudinal distal portion 2102. The light guide 2100 can includea first diverting feature 2124 located at a distal portion of the firstlight guide and configured to direct light from within the first lightguide toward a first focusing element 2104. In some examples, the firstfocusing element 2104 can be configured to direct light from within thelight guide 2100 to a location in the balloon fluid away from alongitudinal axis 2108 of the first light guide 2100. In some examples,the light guide 2100 can include a second diverting feature 2126, wherethe second diverting feature is located at a distal portion of the firstlight guide and configured to direct light from within the first lightguide toward a second focusing element 2106. In some examples, thesecond focusing element 2106 can be configured to direct light fromwithin the light guide 2100 to a location in the balloon fluid away froma longitudinal axis 2108 of the elongate shaft.

The first focusing element 2104 can be configured to direct light 2110from within the light guide 2100 to a first location 2116 at a firstdistance 2112 from the first light guide 2100, which is spaced away fromthe longitudinal axis 2108 of the light guide 2100 to initiate plasmaformation in the balloon fluid at the first location 2116 and to causerapid bubble 2120 formation, thereby imparting pressure waves upon thevascular lesion. The second focusing element 2106 can be configured todirect light 2110 from within the light guide 2100 to a second location2118 at a second distance 2114 from the first light guide 2100, which isspaced away from the longitudinal axis 2108 of the light guide 2100 toinitiate plasma formation in the balloon fluid away at the secondlocation 2118 and to cause rapid bubble 2122 formation, therebyimparting pressure waves upon the vascular lesion. In the embodimentshown in FIG. 21 , the first distance 2112 and second distance 2114 arethe same. In some embodiments, the first distance 2112 and seconddistance 2114 can be different. It will be appreciated that thediverting features can be tailored to increase or decrease the distancethat the light from within the light guide is focused at a locationspaced away from the longitudinal axis.

Diverting features suitable for use with the focusing elements hereinsuch as the embodiment of FIG. 21 , can include, but are not to belimited to, any feature of the system herein that diverts light from thelight guide away from its axial path toward a side surface portion ofthe light guide. Examples include a reflector, a refracting element, anda fiber diffuser, as will be discussed in more detail below. It will beappreciated that the light guides used in the catheter systems hereincan include a second, third, fourth, fifth, or sixth focusing element.In some embodiments, the light guides herein can include more than sixfocusing elements. The focusing elements suitable for use herein caninclude one or more structures such as a convex lens, a convex mirror,or a gradient-index (GRIN) lens. In some examples, the focusing elementsutilized in the light guides herein can be a GRIN lens. In otherexamples, the focusing elements utilized in the light guides herein caninclude convex lenses. In yet other embodiments, the focusing elementsutilized in the light guides herein can include convex mirrors. Invarious embodiments, a GRIN lens, convex lens, or convex mirror can beadhered to or fused to a side surface portion or distal tip of the lightguides herein with an optically matched adhesive. Adhesives suitable foruse with the focusing elements herein can include optically matched oroptically mismatched adhesives.

The focusing elements can be located at a distal tip of the light guidesherein or disposed along the longitudinal axis of the light guides. Thefocusing elements described herein can be present in a distal tip of thelight guides or along one or more locations along a longitudinal portionof the light guides.

The light guides including focusing elements as described can be used invarious methods for generating pressure waves to induce fractures in avascular lesion within or adjacent a vessel wall of a blood vessel. Inone embodiment, the method can include advancing a catheter to avascular lesion within the blood vessel, where the catheter includes anelongate shaft, a balloon coupled to the elongate shaft, and at least afirst light guide disposed along the elongate shaft within the balloon.The first light guide can be configured to be placed in opticalcommunication with a light source and a balloon fluid. a first lightguide with a first focusing element located at a distal portion of thefirst light guide. The method can include expanding the balloon from acollapsed configuration suitable for advancing the catheter through apatient's vasculature to a first expanded configuration suitable foranchoring the catheter in position relative to a vascular lesion. Themethod can further include, after expanding the balloon, activating alight source in optical communication with the first light guide todirect light from within the first light guide to a first location at afirst distance away from the distal portion of the first light guide toinitiate plasma formation in the balloon fluid away from the distalportion and to cause rapid bubble formation, thereby imparting pressurewaves upon the vascular lesion. The first location is spaced away fromthe distal tip and is centered on a longitudinal axis of the first lightguide. In various embodiments, the first location can be spaced awayfrom the distal end of the light guide such that it is off-axis from thelongitudinal axis of the light guide, or away from the longitudinal axisof the light guide. The method can further include, after activating thelight source, further expanding the balloon from the first expandedconfiguration to a second further expanded configuration.

Fortified Balloon Inflation Fluids (FIGS. 22 and 23)

The balloons herein can be inflated with a fortified balloon inflationfluid that is configured to reduce a threshold for inducing plasmaformation in the fortified balloon inflation fluid when compared to abase inflation fluid. The fortified balloon inflation fluid can be usedin the catheter systems embodied herein. Briefly, the fortified ballooninflation fluid can be used in a catheter system for imparting pressureto induce fractures in a vascular lesion within or adjacent a bloodvessel wall. The catheter systems can include a catheter that can beconfigured to advance to the vascular lesion located within or adjacenta blood vessel. The catheter can include an elongate shaft, where aballoon can be coupled to the elongate shaft, and where the balloonincludes a balloon wall. The elongate shaft can define an inflationlumen, where the inflation lumen can be in fluid communication with theballoon at a distal portion of the elongate shaft and in fluidcommunication with a fluid source at a proximal end of the elongateshaft. The balloon can be configured to expand from a collapsedconfiguration suitable for advancing the catheter through a patient'svasculature to a first expanded configuration suitable for anchoring thecatheter in position relative to a vascular lesion. The balloon can alsobe configured to expand to a second further expanded configuration. Thecatheter suitable for use with the fortified balloon inflation fluid canassume many configurations as discussed elsewhere herein.

The fortified balloon inflation fluids described herein can include abase inflation fluid and a fortification component. The fortificationcomponent can reduce a threshold for inducing plasma formation in thefortified balloon inflation fluid compared to the base inflation fluid.In some embodiments, the fortification component can include carbon oriron. In some embodiments the fortification element can include irondextran. In other embodiments, the fortification component can includecarbon. In yet other embodiments, the fortification component caninclude nanoparticles. Various examples of fortification componentssuitable for use herein include, but are not to be limited to, ironnanoparticles, gold nanoparticles, copper nanoparticles, carbonnanoparticles, carbon nanotubes, including, but not to be limited tosingle walled carbon nanotubes or double walled carbon nanotubes ormixtures thereof, gold-coated carbon nanotubes, or copper-coated carbonnanotubes. The fortification component can modify various physicalparameters of the fortified balloon inflation fluid, such as, but notlimited to, viscosity, density, or surface tension. The fortificationcomponent can be configured to increase or decrease one or more theviscosity, density, or surface tension of the fortified ballooninflation fluid compared to the base inflation fluid.

The base inflation fluids herein can include those having a mixture ofsaline and contrast medium. The ratios of the saline and contrast mediumcan be tailored for treatment at vascular lesion within a vessel wall.In some embodiment, the saline and contrast medium can be present withinthe base inflation fluid in a ratio of saline to contrast medium of25:75 volume percent to 75:25 volume percent. In some examples, theratio of saline to contrast medium within the base inflation fluid canbe 25:75 volume percent. In other examples, the ratio of saline tocontrast medium within the base inflation fluid can be 50:50 volumepercent. In yet other examples, the ratio of saline to contrast mediumwithin the base inflation fluid can be 75:25 volume percent.

Fortified balloon inflation fluids having iron dextran as thefortification component can include a concentration of iron dextran fromat least 0.0001 (millimole per liter) mmol/L to 1.0 mmol/L. In someembodiments, the concentration of iron dextran can be greater than orequal to 0.0001 mmol/L, 0.0002 mmol/L, 0.0003 mmol/L, 0.0004 mmol/L,0.0005 mmol/L, 0.0006 mmol/L, 0.0007 mmol/L, 0.0008 mmol/L, 0.0009mmol/L, 0.001 mmol/L, 0.002 mmol/L, 0.003 mmol/L, 0.004 mmol/L, 0.005mmol/L, 0.006 mmol/L, 0.007 mmol/L, 0.008 mmol/L, 0.009 mmol/L, 0.01mmol/L, 0.02 mmol/L, 0.03 mmol/L, 0.04 mmol/L, 0.05 mmol/L, 0.06 mmol/L,0.07 mmol/L, 0.08 mmol/L, 0.09 mmol/L, 0.1 mmol/L, 0.2 mmol/L, 0.3mmol/L, 0.4 mmol/L, 0.5 mmol/L, 0.6 mmol/L, 0.7 mmol/L, 0.8 mmol/L, 0.9mmol/L, or 1.0 mmol/L or can be an amount falling within a rangeincluding any of the foregoing.

Fortified balloon inflation fluids having nanoparticles as thefortification component can include a concentration of nanoparticlesfrom at least 0.01 weight per volume percent (w/v %) to 15 w/v %. Insome embodiments, the concentration of nanoparticles present in thefortified balloon inflation fluids can be greater than or equal to 0.01w/v %, 0.02 w/v %, 0.03 w/v %, 0.04 w/v %, 0.05 w/v %, 0.06 w/v %, 0.07w/v %, 0.08 w/v %, 0.09 w/v %, 0.10 w/v %, 0.2 w/v %, 0.3 w/v %, 0.4 w/v%, 0.5 w/v %, 0.6 w/v %, 0.7 w/v %, 0.8 w/v %, 0.9 w/v %, 1 w/v %, 2 w/v%, 3 w/v %, 4 w/v %, 5 w/v %, 6 w/v %, 7 w/v %, 8 w/v %, 9 w/v %, 10 w/v%, 11 w/v %, 12 w/v %, 13 w/v %, 14 w/v %, or 15 w/v %, or can be anamount falling within a range including any of the foregoing.

The fortified balloon inflation fluid can be used in catheter systemsherein that include a first light guide disposed along the elongateshaft and within the balloon, where the first light guide can beconfigured to be placed in optical communication with a light source andthe fortified balloon inflation fluid. The fortified balloon inflationfluid can be used in catheter systems herein that include a second lightguide, a third light guide, a fourth light guide, or more than fourlight guides. The light guides suitable for use with the fortifiedballoon inflation fluid can include any of the light guides configuredas described elsewhere herein. The light source used with the fortifiedballoon inflation fluid can be configured to provide sub-millisecondpulses of a light from the light source to at least the first lightguide, thereby initiating plasma formation in the fortified ballooninflation fluid, causing rapid bubble formation, and imparting pressurewaves upon the vascular lesion.

The fortification component can be included as a coating on one or moresurfaces of the catheter systems herein, where it can be solvated by abase inflation fluid prior to use in treatment at a vascular lesions.Referring now to FIG. 22, a longitudinal cross section of a catheter2200 is shown in accordance with various embodiments herein. Thecatheter 2200 can be used in a catheter system for imparting pressure toinduce fractures in a vascular lesion within or adjacent a blood vesselwall. The catheter 2200 can be configured to advance to the vascularlesion located within or adjacent a blood vessel. The catheter 2200 caninclude an elongate shaft 102 and a balloon 122 coupled to the elongateshaft 102. The balloon 122 can include a balloon wall. The catheter 2200can include a fortification component coating 2202 disposed on an insidesurface of the balloon wall and in fluid communication with a baseinflation fluid. The fortification component coating 2202 can include afortification component that comprises carbon or iron, as discussedherein.

The balloon 122 of catheter 2200 can be configured to expand from acollapsed configuration suitable for advancing the catheter 2200 througha patient's vasculature to a first expanded configuration suitable foranchoring the catheter 2200 in position relative to a vascular lesion.The balloon 122 of catheter 2200 can be inflated with a base inflationfluid, where the base inflation fluid is configured to solvate thefortification component coating 2202 on the inside surface of theballoon wall to form a fortified balloon inflation fluid. Thefortification component of the fortified balloon inflation fluid can beconfigured to reduce a threshold for inducing plasma formation in thefortified balloon inflation fluid compared to the base inflation fluid.

The catheter 2200 can include a first light guide 2204 disposed alongthe elongate shaft 102 and within the balloon 122, the first light guide2204 can be configured to be placed in optical communication with alight source and the fortified balloon inflation fluid. The catheter2200 can also include a second light guide coupled to the elongateshaft, where the second light guide can be in optical communication withthe light source and the fortified balloon inflation fluid. The lightsource can be configured to provide sub-millisecond pulses of light fromthe light source to at least the first light guide 2204, and if presentany additional light guides, thereby initiating plasma formation in thefortified balloon inflation fluid, causing rapid bubble formation, andimparting pressure waves upon the vascular lesion. The first light guide2204 can be an optical fiber and the light source can be a laser, bothof which are described in more detail elsewhere herein.

The catheters herein can also include a fortification component within afortification component coating disposed along the elongate shaft.Referring now to FIG. 23 , a longitudinal cross section of a catheter2300 is shown in accordance with various embodiments herein. Catheter2300 is similar to catheter 2200 of FIG. 22 , in that it has similarcomponents including an elongate shaft 102 and a balloon 122 coupled tothe elongate shaft 102. The balloon 122 can include a balloon wall. Thecatheter 2300 can include a fortification component coating 2302disposed on a surface of the elongate shaft 102 and in fluidcommunication with the base inflation fluid. The fortification componentcoating 2302 can include a fortification component that comprises carbonor iron, as discussed herein.

The balloon 122 of catheter 2300 can be configured to expand from acollapsed configuration suitable for advancing the catheter 2300 througha patient's vasculature to a first expanded configuration suitable foranchoring the catheter 2300 in position relative to a vascular lesion.The balloon 122 of catheter 2300 can be inflated with a base inflationfluid, where the base inflation fluid is configured to solvate thefortification component coating 2302 disposed on a surface of theelongate shaft to form a fortified balloon inflation fluid. Thefortification component of the fortified balloon inflation fluid can beconfigured to reduce a threshold for inducing plasma formation in thefortified balloon inflation fluid compared to the base inflation fluid.

The catheter 2300 can include a first light guide 2304 disposed alongthe elongate shaft 102 and within the balloon 122, the first light guide2304 can be configured to be placed in optical communication with alight source and the fortified balloon inflation fluid. The catheter2300 can also include a second light guide coupled to the elongateshaft, where the second light guide can be in optical communication withthe light source and the fortified balloon inflation fluid. The lightsource can be configured to provide sub-millisecond pulses of light fromthe light source to at least the first light guide 2304, and if presentany additional light guides, thereby initiating plasma formation in thefortified balloon inflation fluid, causing rapid bubble formation, andimparting pressure waves upon the vascular lesion. The first light guide2304 can be an optical fiber and the light source can be a laser, bothof which are described in more detail elsewhere herein.

The fortified balloon inflation media described can be used in variousmethods for generating pressure waves to induce fractures in a vascularlesion within or adjacent a vessel wall of a blood vessel. In oneembodiment, the method can include advancing a catheter to a vascularlesion within the blood vessel, where the catheter includes an elongateshaft, a balloon coupled to the elongate shaft, and at least a firstlight guide disposed along the elongate shaft within the balloon. Themethod can include expanding the balloon from a collapsed configurationsuitable for advancing the catheter through a patient's vasculature to afirst expanded configuration suitable for anchoring the catheter inposition relative to a vascular lesion. The step of expanding theballoon can include expanding the balloon with a fortified ballooninflation fluid including a base inflation fluid and a fortificationcomponent, where the fortification component can be configured to reducea threshold for inducing plasma formation in the fortified ballooninflation fluid compared to the base inflation fluid. In variousembodiments, the method of expanding the balloon can include providingthe fortification component as a coating disposed on an inside surfaceof a balloon wall or on the elongate shaft, where the fortificationcomponent coating is in fluid communication with the base inflationfluid, and providing the base inflation fluid to the balloon, where thebase inflation fluid solvates the fortification component coating toform the fortified balloon inflation fluid.

The fortification component can include carbon or iron, where thefortification component can include, but is not to be limited to, irondextran or nanoparticles. Some exemplary nanoparticles include ironnanoparticles, gold nanoparticles, copper nanoparticles, carbonnanoparticles, carbon nanotubes, including, but not to be limited tosingle walled carbon nanotubes or double walled carbon nanotubes ormixtures thereof, gold-coated carbon nanotubes, or copper-coated carbonnanotubes. In various embodiments, after expanding the balloon, themethod can include activating a light source in optical communicationwith the light guide and the fortified balloon inflation fluid toprovide sub-millisecond pulses of light from the light source to thefortified balloon inflation fluid, thereby initiating plasma formationin a fortified balloon inflation fluid and causing rapid bubbleformation, and imparting pressure waves upon the vascular lesion. Insome embodiments, after activating the light source, the method caninclude further expanding the balloon from the first expandedconfiguration to a second further expanded configuration. In otherembodiments, after activating the light source, the method can includefurther expanding the balloon from the first expanded configuration to asecond further expanded configuration.

The light sources herein can be configured to generate sub-millisecondpulses of light to be delivered to a treatment site at a frequency offrom at least 1 hertz (Hz) to 5000 Hz. In some embodiments, the lightsources herein can be configured to generate sub-millisecond pulses oflight to be delivered to a treatment site at a frequency from at least30 Hz to 1000 Hz. In other embodiments, the light sources herein can beconfigured to generate the sub-millisecond pulses of light to bedelivered to a treatment site at a frequency from at least 10 Hz to 100Hz. In yet other embodiments, the light sources herein can be configuredto generate sub-millisecond pulses of light to be delivered to atreatment site at a frequency from at least 1 Hz to 30 Hz. In someembodiments, the light sources herein can be configured to generatesub-millisecond pulses of light to be delivered to a treatment site at afrequency that can be greater than or equal to 1 Hz, 2 Hz, 3 Hz, 4 Hz, 5Hz, 6 Hz, 7 Hz, 8 Hz, or 9 Hz, 10 Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz,70 Hz, 80 Hz, 90 Hz, 100 Hz, 200 Hz, 300 Hz, 400 Hz, 500 Hz, 600 Hz, 700Hz, 800 Hz, 900 Hz, 1000 Hz, 1250 Hz, 1500 Hz, 1750 Hz, 2000 Hz, 2250Hz, 2500 Hz, 2750 Hz, 3000 Hz, 3250 Hz, 3500 Hz, 3750 Hz, 4000 Hz, 4250Hz, 4500 Hz, 4750 Hz, or 5000 Hz or can be an amount falling within arange between any of the foregoing.

Balloons

The balloons suitable for use in the catheter systems herein includethose that can be passed through the vasculature of a patient when in acollapsed configuration. In some embodiments, the balloons herein aremade from silicone. In other embodiments, the balloons herein are madefrom polydimethylsiloxane (PDMS), polyurethane, polymers such as PEBAX™material available from Arkema, which has a location at King of Prussia,Pa., USA, nylon, and the like. In some embodiments, the balloons caninclude those having diameters ranging from 1 millimeter (mm) to 25 mmin diameter. In some embodiments, the balloons can include those havingdiameters ranging from at least 1.5 mm to 12 mm in diameter. In someembodiments, the balloons can include those having diameters rangingfrom at least 1 mm to 5 mm in diameter. In some embodiments, thediameter can be greater than or equal to 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm,2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm,7.0 mm, 7.5 mm, 8.0 mm, 8.5 mm, 9.0 mm, 9.5 mm, 10.0 mm, 10.5 mm, 11.0mm, 11.5 mm, 12.0 mm, 12.5 mm, 13.0 mm, 13.5 mm, 14.0 mm, 14.5 mm, 15.0mm, 15.5 mm, 16.0 mm, 16.5 mm, 17.0 mm, 17.5 mm, 18.0 mm, 18.5 mm, 19.0mm, 19.5 mm, or 20.0 mm, or can be an amount falling within a rangebetween any of the foregoing.

In some embodiments, the balloons herein can include those having alength ranging from at least 5 mm to 300 mm in length. In someembodiments, the balloons herein can include those having a lengthranging from at least 8 mm to 200 mm in length. In some embodiments, thelength of the balloon can be greater than or equal to 5 mm, 10 mm, 20mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, or300 mm, or can be an amount falling within a range between any of theforegoing.

The balloons herein can be inflated to inflation pressures from 1atmosphere (atm) to 70 atm. In some embodiments, the balloons herein canbe inflated to inflation pressures of from at least 20 atm to 70 atm. Insome embodiments, the balloons herein can be inflated to inflationpressures of from at least 6 atm to 20 atm. In some embodiments, theballoons herein can be inflated to inflation pressures of from at least3 atm to 20 atm. In some embodiments, the balloons herein can beinflated to inflation pressures of from at least 2 atm to 10 atm. Insome embodiments, the balloons herein can be inflated to inflationpressures that can be greater than or equal to 1 atm, 2 atm, 3 atm, 4atm, 5 atm, 6 atm, 7 atm, 8 atm, 9 atm, 10 atm, 15 atm, 20 atm, 25 atm,30 atm, 35 atm, 40 atm, 45 atm, 50 atm, 55 atm, 60 atm, 65 atm, or 70atm, or can be an amount falling within a range between any of theforegoing.

The balloons herein can include those having various shapes, including,but not to be limited to, a conical shape, a square shape, a rectangularshape, a spherical shape, a conical/square shape, a conical/sphericalshape, an extended spherical shape, an oval shape, a tapered, shape, abone shape, a stepped diameter shape, an offset shape, or a conicaloffset shape. In some embodiments, the balloons herein can include adrug eluting coating or a drug eluting stent structure. The drug elutioncoating or drug eluting stent can include one or more therapeutic agentsincluding anti-inflammatory agents, anti-neoplastic agents,anti-angiogenic agents, and the like.

Balloon Fluids

Exemplary balloon fluids suitable for use herein can include, but arenot to be limited to one or more of water, saline, contrast medium,fluorocarbons, perfluorocarbons, gases, such as carbon dioxide, and thelike. In some embodiments, the balloon fluids described can be used asbase inflation fluids, discussed elsewhere herein. In some embodiments,the balloon inflation fluids include a mixture of saline to contrastmedium in a volume ratio of 50:50. In some embodiments, the balloonfluids include a mixture of saline to contrast medium in a volume ratioof 25:75. In some embodiments, the balloon fluids include a mixture ofsaline to contrast medium in a volume ratio of 75:25. The balloon fluidssuitable for use herein can be tailored on the basis of composition,viscosity, and the like in order to manipulate the rate of travel of thepressure waves therein. The balloon fluids suitable for use herein arebiocompatible. A volume of balloon fluid can be tailored by the chosenlight source and the type of balloon fluid used.

In some embodiments, the contrast agents used in the contrast mediaherein can include, but are not to be limited to, iodine-based contrastagents, such as ionic or non-ionic iodine-based contrast agents. Somenon-limiting examples of ionic iodine-based contrast agents includediatrizoate, metrizoate, iothalamate, and ioxaglate. Some non-limitingexamples of non-ionic iodine-based contrast agents include iopamidol,iohexol, ioxilan, iopromide, iodixanol, and ioversol. In otherembodiments, non-iodine based contrast agents can be used. Suitablenon-iodine containing contrast agents can include gadolinium (III)-basedcontrast agents. Suitable fluorocarbon and perfluorocarbon agents caninclude, but are not to be limited to, agents such as theperfluorocarbon dodecafluoropentane (DDFP, C5F12).

The balloon fluids herein can include those that include absorptiveagents that can selectively absorb light in the ultraviolet (e.g., atleast 10 nanometers (nm) to 400 nm), visible region (e.g., at least 400nm to 780 nm), and near-infrared region of the electromagnetic spectrum(e.g., at least 780 nm to 2.5 μm), or in the far-infrared region of theelectromagnetic spectrum of at least 10 nm to 2.5 micrometers (μm).Suitable absorptive agents can include those with absorption maximaalong the spectrum from at least 10 nm to 2.5 μm. In variousembodiments, the absorptive agent can be those that have an absorptionmaximum matched with the emission maximum of the laser used in thecatheter system. By way of non-limiting examples, various lasersdescribed herein can include neodymium:yttrium-aluminum-garnet(Nd:YAG−emission maximum=1064 nm) lasers. holmium:YAG (Ho:YAG−emissionmaximum=2.1 μm) lasers, or erbium:YAG (Er:YAG−emission maximum=2.94 μm).In some embodiments, the absorptive agents used herein can be watersoluble. In other embodiments, the absorptive agents used herein are notwater soluble. In some embodiments, the absorptive agents used in theballoon fluids herein can be tailored to match the peak emission of thelight source. Various light sources having emission wavelengths of atleast 10 nanometers to 1 millimeter are discussed elsewhere herein.

In some embodiments, introduction of the balloon fluid causes theexpansion of the balloon from a collapsed configuration to a firstexpanded configuration and from a first expanded configuration to asecond further expanded configuration. In addition or alternatively, theexpansion of the balloon can be accomplished using a shape-memorymaterial or other means.

Light Guides (FIGS. 24-29)

The light guides herein can include an optical fiber or flexible lightpipe. The light guides herein can be thin and flexible and can allowlight signals to be sent with very little loss of strength. The lightguides herein can include a core surrounded by a cladding about itscircumference. In some embodiments, the core can be a cylindrical coreor a partially cylindrical core. The core and cladding of the lightguides can be formed from one or more materials, including but notlimited to one or more types of glass, silica, or one or more polymers.The light guides may also include a protective coating, such as apolymer. It will be appreciated that the index of refraction of the corewill be greater than the index of refraction of the cladding.

Each light guide can guide light along its length to a distal portionhaving at least one optical window. The light guides can create a lightpath as portion of an optical network including a light source. Thelight path within the optical network allows light to travel from onepart of the network to another. Both the optical fiber or the flexiblelight pipe can provide a light path within the optical networks herein.

The light guides herein can assume many configurations about theelongate shaft of the catheters described herein. In some embodiments,the light guides can run parallel to the longitudinal axis of theelongate shaft of the catheter. In some embodiments, the light guidescan be disposed spirally or helically about the longitudinal axis of theelongate shaft of the catheter. In some embodiments, the light guidescan be physically coupled to the elongate shaft. In other embodiments,the light guides can be disposed along the length of the outer diameterof the elongate shaft. In yet other embodiments the light guides hereincan be disposed within one or more light guide lumens within theelongate shaft. Various configurations for the elongate shafts and lightguide lumens will be discussed below.

The light guides herein can include various configurations at a distalportion of the light guide. Referring now to FIGS. 24-29 , schematiccross-sectional views of the distal portions of various shaped lightguides are shown in accordance with various embodiments herein. In FIG.24 , a schematic cross-sectional view of a light guide 2400 is shown.Light guide 2400 includes a cylindrical end shape. In some embodiments,the end of the light guide can have a tapered shape. By way of example,in FIG. 25 a schematic cross-sectional view of a light guide 2500 havinga tapered end shape is shown. In some embodiments, the end of the lightguide can have an angled shape. By way of example, in FIG. 26 aschematic cross-sectional view of a light guide 2600 is shown. Lightguide 2600 includes an angled end shape. In some embodiments, a lightguide with an angled shape can include a diverting feature. By way ofexample, in FIG. 27 a schematic cross-sectional view of a light guide2700 is shown. The light guide 2700 also includes a diverting feature2706 at the distal portion to direct the light 2704 within the lightguide toward the side surface portion 2708 of the light guide. Lightguide 2700 is configured such that light 2704 travels from a lightsource (not shown) in the direction from the proximal portion of thelight guide to the distal portion of the light guide 2700, as indicatedby the arrow. Upon contact with the diverting feature 2706, the light2704 is diverted, or reflected, within the light guide 2700.

In some embodiments, a diverting feature can be included with the lightguide to direct light toward a side surface portion of the distalportion of the light guide. A diverting feature can include any featureof the system herein that diverts light from the light guide away fromits axial path toward a side surface portion of the light guide.Examples include a reflector, a refracting element, and a fiberdiffuser. Fiber diffusers will be discussed in more detail below.

The light guides herein can also include one or more focusing elementsfor directing the origin of a pressure wave away from the distal tip ofthe light guides. By way of example, in FIG. 28 a schematiccross-sectional view of a light guide 2800 is shown. The light guide2800 includes a first convex surface 2802. The first convex surface 2802is configured to direct light away from the distal tip of the lightguide 2800 to generate a pressure wave having an origin point away fromthe surface of the distal tip. In some embodiments, the light guides inaccordance with the embodiments therein can be configured to includemultiple convex surfaces. By way of example, in FIG. 29 a schematiccross-sectional view of a light guide 2900 is shown. The light guide2900 includes a first convex surface 2902 and a second convex surface2904. The first convex surface 2902 and second convex surface 2904 canbe configured to direct light away from the distal tip of the lightguide to generate a plurality of pressure waves each having a pluralityof origin points away from the surface of the distal tip.

In other embodiments, the light guides can form a spiral configurationabout the longitudinal axis of the elongate shaft of the catheter. Insome embodiments, the spiral configuration can run clockwise about thelongitudinal axis of the elongate shaft of the catheter, while in otherembodiments the spiral configuration can run counter-clockwise about thelongitudinal axis of the elongate shaft of the catheter. In someembodiments, the light guides can form a single helix, a double helix, atriple helix, or a quadruple helix about the longitudinal axis of theelongate shaft of the catheter.

The light guides herein can come in various sizes and configurations.The light guides will have a longitudinal axis along the elongate shaftof the light guide and short axis about its circumference. In someembodiments, the light guides can have an outer diameter of about 100μm, including the cladding and the core. In other embodiments, the lightguides can include those that have an outer diameter of from 50 μm to1000 μm including the cladding and the core. The length of the lightguides can include those having a length of from 40 cm to 175 cm. Insome embodiments, the length of the light guides can include thosehaving a length of from 50-150 cm. In some embodiments, the length ofthe light guide can include those having a length of 40 cm, 50 cm, 60cm, 70 cm, 80 cm, 90 cm, 100 cm, 125 cm, 150 cm, or 175 cm. It will beappreciated that the light guides herein can have a usable length thatcan fall within a range, wherein any of the forgoing lengths can serveas the lower or upper bound of the range, provided that the lower boundof the range is a value less than the upper bound of the range.

It will be appreciated that one or more light guides herein can beadhered to the outside surface of the elongate shaft of a catheter, tocreate a catheter. However, in other embodiments, one or more lightguides can be disposed within a lumen of a catheter. In addition, thecatheter may define a lumen for a guidewire having an inner diameter ofabout 0.014 inch (0.356 mm). In some embodiments, the catheter caninclude those having an inner diameter of about 0.018 inch (0.457 mm).In yet other embodiments, the catheter can include those having an innerdiameter of about 0.035 inch (0.889 mm). In some embodiments the lightguides herein can be integrated with a balloon catheter. In someembodiments the light guides herein can be integrated into a guidewire.In embodiments where the light guide is integrated into a guidewire, theresulting catheter can be used independently or can be used with variousother balloon catheters.

Lumens of the Elongate Shaft (FIGS. 30-41)

The elongate shafts herein can include one or more lumens that span thelength of the elongate shaft. Referring now to FIGS. 30-41 , schematiccross-sectional views of various embodiments of an elongate shaft havingmultiple lumens are shown in accordance with various embodiments herein.In some embodiments, the elongate shaft can define a guidewire lumen. Insome embodiments, the elongate shaft defines an inflation lumensurrounding the guidewire lumen, where the inflation lumen is in fluidcommunication with a balloon at a distal portion of the elongate shaft.In other embodiments, the elongate shaft defines an inflation lumendisposed alongside the guidewire lumen, where the inflation lumen is influid communication with a balloon at a distal portion of the elongateshaft. In yet other embodiments, the elongate shaft defines at least onecontrol lumen, at least one light guide lumen, or at least one drugtherapy lumen.

In the configuration in FIG. 30 , elongate shaft 3000 includesconcentrically disposed guidewire lumen 3002 and an inflation lumen3004. In the configuration in FIG. 31 , elongate shaft 3100 includesguidewire lumen 3102 and an inflation lumen 3104 disposed adjacent toand partially surrounding guidewire lumen 3102. In the configuration inFIG. 32 , elongate shaft 3200 includes guidewire lumen 3202 and aninflation lumen 3204 disposed adjacent to guidewire lumen 3202. In theconfiguration in FIG. 33 , elongate shaft 3300 includes guidewire lumen3302 inflation lumen 3304, and a control lumen 3306. It will beappreciated that the control lumens herein can be used for manypurposes, including, but not to be limited to, blood flow, cooling orheating fluid flow, delivery of a diagnostic or therapeutic agent, lightguides, and the like. In the configuration in FIG. 34 , elongate shaft3400 includes guidewire lumen 3402, inflation lumen 3404, and twocontrol lumens 3406 and 3408. In the configuration in FIG. 35 , elongateshaft 3500 includes guidewire lumen 3502, inflation lumen 3504, andcontrol lumens 3506.

The light guides can be disposed within one or more light guide lumensdisposed within the elongate shafts symmetrically about thecircumference. In some embodiments, the lumens herein can include thosethat are used for blood flow, cooling or heating fluid flow, delivery ofa diagnostic or therapeutic agent, and the like. In the configuration inFIG. 36 , elongate shaft 3600 includes guidewire lumen 3602, light guidelumen 3604, and control lumen 3606. One or more of lumens 3602, 3604 and3606 can serve as an inflation lumen. In the configuration in FIG. 37 ,elongate shaft 3700 includes guidewire lumen 3702, light guide lumen3704, and control lumen 3706. Elongate shaft 3700 includes twoadditional lumens that can both be configured as light guide lumens,control lumens, or both a light guide lumen and control lumen. One ormore of lumens 3702, 3704 and 3706 can serve as an inflation lumen. Inthe configuration in FIG. 38 , elongate shaft 3800 includes guidewirelumen 3802, light guide lumen 3804, and control lumen 3806. Elongateshaft 3800 includes six additional lumens that can be configured asinflation lumens, light guide lumens, control lumens, or any combinationof inflation lumens, light guide lumens and control lumens.

The light guides can be disposed within one or more light guide lumensdisposed within the elongate shafts asymmetrically about thecircumference. In the configuration in FIG. 39 , elongate shaft 3900includes guidewire lumen 3902, light guide lumen 3904, and control lumen3906. Elongate shaft 3900 includes one additional lumen that can beconfigured as a light guide lumen 3904 or a control lumen 3906. In theconfiguration in FIG. 40 , elongate shaft 4000 includes guidewire lumen4002, light guide lumen 4004, and control lumen 4006. Elongate shaft4000 includes three additional lumens that can be configured as lightguide lumens, control lumens, or any combination of light guide lumensand control lumens. In the configuration in FIG. 41 , elongate shaft4100 includes guidewire lumen 4102, light guide lumen 4104, and controllumen 4106. Elongate shaft 4100 includes three additional lumens thatcan be configured as inflation lumens, light guide lumens, controllumens, or any combination of inflation lumens, light guide lumens, andcontrol lumens.

It will be appreciated that the lumens described in FIGS. 30-41 canassume many shapes, including, but not to be limited to, circular shape,square shape, crescent shape, triangular shape, and the like. The lumensof the elongate shafts can by symmetrically disturbed in the elongateshaft, asymmetrically distributed, or concentrically distributed. Itwill be further appreciated that the light guide lumens herein can becoated along the longitudinal length of the elongate shaft with areflective material capable of propagating light along the elongateshaft from a distal light source to the proximal portion of thecatheter, so that the lumen itself can act as a light guide without aseparate fiber optic structure.

Diverting Features

The diverting features suitable for use herein include a reflectingelement, a refracting element, and a fiber diffuser. In someembodiments, the diverting feature can be a reflecting element. In someembodiments, the diverting feature can be a refracting element. In someembodiments, the diverting feature can be a fiber diffuser.

A fiber diffuser can direct light from within a light guide to exit at aside surface portion of the light guide. The fiber diffusers describedherein can be created several ways. In some embodiments, the fiberdiffusers can be created by micro-machining the surface of the distalportion of a light guide with a CO₂ laser. In some embodiments, a fusedsilica coating can be applied to the distal portion of the light guide.In other embodiments, the fiber diffuser can be formed from a glass, apolymer, or a metal coating on the distal portion of the light guide. Inother embodiments, the fiber diffuser can be formed by a fiber Bragggrating on the distal portion of the light guide. In some embodiments,the fiber diffuser can include a machined portion of the light guide, alaser-machined portion of the light guide, fiber Bragg gratings, a fusedsplicing, a fused splicing forming at least one internal mirror, and asplicing of two or more diffuse regions.

Suitable materials for a fiber diffuser can include, but are not belimited to, the materials of the light guide core or light guidecladding, ground glass, silver coated glass, gold coated glass, TiO2,and other materials that will scatter and not significantly absorbed thelight wavelength of interest. One method that can be used to create auniform diffuser in a light guide, optical component, or materials is toutilize scattering centers on the order of at least 50 nanometers to 5micrometers in size. The scattering centers can have a distributionabout 200 nanometers in size.

The diverting features suitable for focusing light away from the tip ofthe light guides herein can include, but are not to be limited to, thosehaving a convex surface, a gradient-index (GRIN) lens, and a mirrorfocus lens.

Light Sources

The light sources suitable for use herein can include various types oflight sources including lasers and lamps. Suitable lasers can includeshort pulse lasers on the sub-millisecond timescale. In someembodiments, the light source can include lasers on the nanosecond (ns)timescale. The lasers can also include short pulse lasers on thepicosecond (ps), femtosecond (fs), and microsecond (us) timescales. Itwill be appreciated that there are many combinations of laserwavelengths, pulse widths and energy levels that can be employed toachieve plasma in the balloon fluid of the catheters described herein.In various embodiments, the pulse widths can include those fallingwithin a range including from at least 10 ns to 200 ns. In someembodiments, the pulse widths can include those falling within a rangeincluding from at least 20 ns to 100 ns. In another embodiment, thepulse widths can include those falling within a range including from atleast 50 ns to 1500 ns. In other embodiments, the pulse widths caninclude those falling within a range including from at least 1 ns to5000 ns. Still alternatively, the pulse widths can fall outside of theforegoing ranges.

Exemplary nanosecond lasers can include those within the UV to IRspectrum, spanning wavelengths of about 10 nanometers to 1 millimeter.In some embodiments, the light sources suitable for use in the cathetersystems herein can include those capable of producing light atwavelengths of from at least 750 nm to 2000 nm. In some embodiments, thelight sources can include those capable of producing light atwavelengths of from at least 700 nm to 3000 nm. In some embodiments, thelight sources can include those capable of producing light atwavelengths of from at least 100 nm to 10 micrometers (μm). Nanosecondlasers can include those having repetition rates of up to 200 kHz. Insome embodiments, the laser can include a Q-switchedthulium:yttrium-aluminum-garnet (Tm:YAG) laser. In some embodiments, thelaser can include a neodymium:yttrium-aluminum-garnet (Nd:YAG),holmium:yttrium-aluminum-garnet (Ho:YAG), erbium:yttrium-aluminum-garnet(Er:YAG), excimer laser, helium-neon laser, carbon dioxide laser, aswell as doped, pulsed, fiber lasers.

Pressure Waves

The catheters herein can generate pressure waves having maximumpressures in the range of at least 1 megapascal (MPa) to 100 MPa. Themaximum pressure generated by a particular catheter will depend on thelight source, the absorbing material, the bubble expansion, thepropagation medium, the balloon material, and other factors. In someembodiments, the catheters herein can generate pressure waves havingmaximum pressures in the range of at least 2 MPa to 50 MPa. In otherembodiments, the catheters herein can generate pressure waves havingmaximum pressures in the range of at least 2 MPa to 30 MPa. In yet otherembodiments, the catheters herein can generate pressure waves havingmaximum pressures in the range of at least 15 MPa to 25 MPa. In someembodiments, the catheters herein can generate pressure waves havingpeak pressures of greater than or equal to 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa,15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa,24 MPa, or 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31 MPa, 32MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, or50 MPa. It will be appreciated that catheters herein can generatepressure waves having operating pressures or maximum pressures that canfall within a range, wherein any of the forgoing numbers can serve asthe lower or upper bound of the range, provided that the lower bound ofthe range is a value less than the upper bound of the range.

Therapeutic treatment can act via a fatigue mechanism or a brute forcemechanism. For a fatigue mechanism, operating pressures would be aboutat least 0.5 MPa to 2 MPa, or about 1 MPa. For a brute force mechanism,operating pressures would be about at least 20 MPa to 30 MPa, or about25 MPa. Pressures between the extreme ends of these two ranges may actupon a calcified lesion using a combination of a fatigue mechanism and abrute force mechanism.

The pressure waves described herein can be imparted upon the treatmentsite from a distance within a range from at least 0.1 millimeters (mm)to 25 mm extending radially from a longitudinal axis of a catheterplaced at a treatment site. In some embodiments, the pressure waves canbe imparted upon the treatment site from a distance within a range fromat least 10 mm to 20 mm extending radially from a longitudinal axis of acatheter placed at a treatment site. In other embodiments, the pressurewaves can be imparted upon the treatment site from a distance within arange from at least 1 mm to 10 mm extending radially from a longitudinalaxis of a catheter placed at a treatment site. In yet other embodiments,the pressure waves can be imparted upon the treatment site from adistance within a range from at least 1.5 mm to 4 mm extending radiallyfrom a longitudinal axis of a catheter placed at a treatment site. Insome embodiments, the pressure waves can be imparted upon the treatmentsite from a range of at least 2 MPa to 30 MPa at a distance from 0.1 mmto 10 mm. In some embodiments, the pressure waves can be imparted uponthe treatment site from a range of at least 2 MPa to 25 MPa at adistance from 0.1 mm to 10 mm. In some embodiments, the pressure wavescan be imparted upon the treatment site from a distance that can begreater than or equal to 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm,0.7 mm, 0.8 mm, or 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8mm, 9 mm, or 10 mm, or can be an amount falling within a range betweenany of the foregoing.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. It should also be notedthat the term “or” is generally employed in its sense including “and/or”unless the content clearly dictates otherwise.

It should also be noted that, as used in this specification and theappended claims, the phrase “configured” describes a system, apparatus,or other structure that is constructed or configured to perform aparticular task or adopt a particular configuration. The phrase“configured” can be used interchangeably with other similar phrases suchas arranged and configured, constructed and arranged, constructed,manufactured and arranged, and the like.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

As used herein, the recitation of numerical ranges by endpoints shallinclude all numbers subsumed within that range (e.g., 2 to 8 includes2.1, 2.8, 5.3, 7, etc.).

The headings used herein are provided for consistency with suggestionsunder 37 CFR 1.77 or otherwise to provide organizational cues. Theseheadings shall not be viewed to limit or characterize the invention(s)set out in any claims that may issue from this disclosure. As anexample, although the headings refer to a “Field,” such claims shouldnot be limited by the language chosen under this heading to describe theso-called technical field. Further, a description of a technology in the“Background” is not an admission that technology is prior art to anyinvention(s) in this disclosure. Neither is the “Summary” to beconsidered as a characterization of the invention(s) set forth in issuedclaims.

The embodiments described herein are not intended to be exhaustive or tolimit the invention to the precise forms disclosed in the followingdetailed description. Rather, the embodiments are chosen and describedso that others skilled in the art can appreciate and understand theprinciples and practices. As such, aspects have been described withreference to various specific and preferred embodiments and techniques.However, it should be understood that many variations and modificationsmay be made while remaining within the spirit and scope herein.

What is claimed is:
 1. A catheter system for imparting pressure toinduce fractures in a treatment site within or adjacent a vessel wall,comprising: a catheter that is configured to be advanced to thetreatment site, the catheter comprising an elongate shaft, a ballooncoupled to the elongate shaft, and a first energy guide disposed alongthe elongate shaft, the elongate shaft defining a first recess withinthe balloon, the balloon being configured to be filled with a balloonfluid, the first energy guide being configured to be positioned at leastpartially within the balloon and the balloon fluid, the first energyguide including a first portion that is configured to extend into thefirst recess; and a first protection structure that contacts the firstportion of the first energy guide, the first protection structure beingconfigured to provide structural protection to the first portion of thefirst energy guide.
 2. The catheter system of claim 1 wherein the firstprotection structure includes a potting material that at least partiallyfills the first recess, the potting material being optically matched tothe first energy guide.
 3. The catheter system of claim 1 wherein thefirst energy guide includes a light guide.
 4. The catheter system ofclaim 3 wherein the first energy guide further includes a divertingfeature selected from the group consisting of a reflecting element, arefracting element, and a fiber diffuser.
 5. The catheter system ofclaim 4 wherein the diverting feature comprises a fiber diffuserselected from the group consisting of a machined portion of the lightguide, a laser-machined portion of the light guide, fiber Bragggratings, a fused splicing forming at least one internal mirror, and asplicing of two or more diffuse regions.
 6. The catheter system of claim1 wherein the first recess is a longitudinal recess along a longitudinalsurface of the elongate shaft.
 7. The catheter system of claim 1 whereinthe first energy guide is in optical communication with an energysource, the energy source being configured to selectively provideprovides pulses of energy through the first energy guide to the balloonfluid so that plasma formation and rapid bubble formation in the balloonfluid occur.
 8. The catheter system of claim 7 wherein the energy sourceis a laser.
 9. The catheter system of claim 1 further comprising a firstfocusing element disposed along a longitudinal axis of the energy guide.10. The catheter system of claim 9 wherein the first focusing element isbe configured to direct energy from within the first energy guide to afirst location at a first distance from the first energy guide.
 11. Acatheter system for imparting pressure to induce fractures in atreatment site within or adjacent a vessel wall, comprising: a catheterthat is configured to be advanced to the treatment site, the cathetercomprising an elongate shaft, a balloon coupled to the elongate shaft,and a first light guide disposed along the elongate shaft, the elongateshaft defining a first recess within the balloon, the balloon beingconfigured to be filled with a balloon fluid, the first light guidebeing configured to be positioned at least partially within the balloonand the balloon fluid, the first light guide including a first portionthat is configured to extend into the first recess, the first lightguide being in optical communication with a light source, the lightsource being configured to selectively provide provides pulses of lightthrough the first light guide to the balloon fluid so that plasmaformation and rapid bubble formation in the balloon fluid occur; and afirst protection structure that contacts the first portion of the firstlight guide, the first protection structure being configured to providestructural protection to the first portion of the first light guide. 12.The catheter system of claim 1 wherein the first protection structureincludes a potting material that at least partially fills the firstrecess, the potting material being optically matched to the first lightguide.
 13. The catheter system of claim 1 wherein the first light guidefurther includes a diverting feature selected from the group consistingof a reflecting element, a refracting element, and a fiber diffuser. 14.The catheter system of claim 13 wherein the diverting feature comprisesa fiber diffuser selected from the group consisting of a machinedportion of the light guide, a laser-machined portion of the light guide,fiber Bragg gratings, a fused splicing forming at least one internalmirror, and a splicing of two or more diffuse regions.
 15. The cathetersystem of claim 1 wherein the first recess is a longitudinal recessalong a longitudinal surface of the elongate shaft.
 16. The cathetersystem of claim 7 wherein the light source is a laser.
 17. The cathetersystem of claim 1 further comprising a first focusing element disposedalong a longitudinal axis of the light guide.
 18. The catheter system ofclaim 17 wherein the first focusing element is be configured to directenergy from within the first light guide to a first location at a firstdistance from the first light guide.
 19. The catheter system of claim 1further comprising a second focusing element disposed along alongitudinal axis of the light guide, the second focusing element beingspaced away from the first focusing element.
 20. A catheter system forimparting pressure to induce fractures in a treatment site within oradjacent a vessel wall, comprising: a catheter that is configured to beadvanced to the treatment site, the catheter comprising an elongateshaft, a balloon coupled to the elongate shaft, and an energy guidedisposed along the elongate shaft, the elongate shaft defining a firstrecess within the balloon, the energy guide including a first portionthat is configured to extend into the first recess; and a firstprotection structure that contacts the first portion of the energyguide, the first protection structure being configured to providestructural protection to the first portion of the energy guide.